The environmental impact of maize cultivation in the ... · of profitable forage with maize...

The environmental impact of maize cultivation in the European Union:Practical options for the improvment of the environmental impact.

- Case study Germany -

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Research Centre for Agriculture and Environment

in cooperation with the Department of Forage and Grass Research

of the Institute for Agronomy and Plant Breeding,

Georg-August-University of Göttingen

Göttingen, in november 1999

Environmental impact of maize cultivation: case study Germany 1

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1.1 Utilization

The cultivation of Maize (]HD�PD\V L.) in Germany is undertaken primarily to produce feedfor cows, pigs and poultry (maize for silage including green-maize, grain maize, corn cobmix, maize coarse meal with husks). As well as being used for producing sugar, grain is alsoused by the food industry to produce maize-meal-products, snacks, cornflakes etc., and inpharmaceutical processes. As a renewable raw material, maize starch is used in themanufacture of paper and cardboard (it is an important additive in wastepaper processing).New packing and impact protection materials are produced in new extraction mouldingprocedures from maize-semolina. Sugar-maize, normally marketed directly as whole earmaize, is finding wider markets (GERMAN MAIZE-COMMITTEE E.V. 1999, FEDERALMINISTRY OF AGRICULTURE 1995, CHAMBER OF AGRICULTURE HANNOVER1995).How the maize will be used determines the procedure of the maize cultivation. In Germany,maize is grown as grain maize, ear maize or maize for silage. Grain maize: The ripe grainsare harvested and used as feed or industrially processed. Ear maize becomes corn-cob-mix(CCM) or coarse maize meal with husks (used exclusively for forage) and is normally not asripe because harvesting begins earlier. Parts of the maize ear as well as the huskssurrounding the maize ear are harvested. They are crushed and preserved in a humidenvironment and used as a high energy forage. Silage maize is harvested as a whole plant,chopped into small pieces and preserved as basic forage even if the maize grains are not yetquite ripe.In Germany the area cultivated with maize amounted to 1.58 million ha in 1998 (GERMANMAIZE-COMMITTEE E.V. 1999). The largest maize-cultivating federal states of Germanyare Bavaria with approximately 400,000 ha and Lower Saxony with almost 300,000 ha,followed by North Rhine-Westphalia, Baden-Württemberg and Brandenburg (Figure 1).In Germany, 78% of the maize-cultivated acreage is maize for silage, 16% is grain maizeand 6% is corn cob mix (Figure 2). The acreage of maize for silage includes the relativelysmall arable lands used for maize coarse meal with husks and green-maize which is usedonly as fresh feed. It can be seen that there is a strong concentration of silage maizecultivation in the northwest and southern parts of Germany because many intensive fatteningbull farms, partially interconnected with dairy farming, are located in these regions (North-West-Germany and South-East-Bavaria). This leads to a high amount of semi-liquid manure.The semi-liquid manure can easily be spread on land with maize-cultivation because themaize tolerates an excess fertilization with nitrogen without yield loss.


maize-cultivated area (total):

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116.750 ha11%77.317 ha

8%

3.182 ha8%

293.848 ha16%

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74.530 ha 8%

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392.583 ha18%

131.998 ha15%

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20.348 ha 5%

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216.894 ha20%

86.089 ha 8%

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75.834 ha13%

1.576.159 ha = 13% of the arable land

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Grain maize has the highest demand for warmth of all maize. This is why there is aconcentration of maize in Southern Germany, i.e. in the Rhine-valley (Baden-Württemberg)and in the main and lower Rott valley (Bavaria) as well as near Passau (Bavaria), primarilyin market-fruit-farms. Early and middle-early varieties of maize grow also in climaticallymore unfavourable border-situations of the low mountain regions and in the lowlands ofNorth-West-Germany. Here, the dominant areas of cultivation are on the intensive livestockfarms of Lower Saxony (Südoldenburg) and North Rhine-Westphalia (Westphalia-Lippe) –mainly on farms with livestock which have a supply of manure.


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Hesse

Thuringia

Saxony

Schleswig-Holstein

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Mecklenburg-West. Pom.

Brandenburg

Baden-Württemberg

North Rhine-Westphalia

Lower-Saxony

Bavaria

Corn-Cob-Mix

Grain Maize

Maize for Silage

Germany total* = 1.576.159 hatherefrom Maize for Silage = 1.235.130 ha

Grain Maize = 251.106 haCorn-Cob-Mix = 89.923 ha

* incl. Berlin, Bremen, Hamburg

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(in numbers)

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1.2 Development of the maize acreage

Since the mid-1960’s, the cultivation of maize had increased substantially in both parts ofGermany (Figure 3). Across the whole of Germany maize is now grown on 13% of thearable land. The main factor which has enabled this increase is the development of newstrains of maize which will grow in cooler areas. The development of Triazin, e.g. Atrazin,for weed control, improvements in harvesting and preservation technologies and in seedingtechniques (e.g. single grain seeds), have all supported this increase.In terms of acerage, the expansion of maize for silage acreage has already reached its peak inthe former FRG in 1986. Previously grown labour-intensive forage crops (fodder-beets,grass and clover-grass, lucerne) were substituted with maize for silage. In 1992, 73% of theacreage of forage crops in Germany were sown with maize for silage. This share hasremained constant since then.


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Maize for SilageGrain Maize/CCM

1999 preliminary

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Maize for SilageGrain Maize/CCM

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Because of the more favourable weather conditions in the south, Southern Germanyexpanded its maize cultivation before the northern areas. In the former GDR, as early as the1970s, more than 300.000 ha maize was grown for forage-production (Figure 4).Today the new federal states produce 30% of the total silage maize and 10% of the grainmaize in Germany. With the change in production-systems of the former GDR and thereduction of livestock husbandry, the land area used for silage maize has fluctuated over thelast few years.Since 1996, the acreage used for maize for silage has decreased in both the new and oldfederal states. The reduced demand for beef (BSE-crisis) has had an effect on livestockproduction and consequently on forage production.

1.3 Factors from an operational view

Grain maize is an important cash crop for farms without livestock - above all in Bavaria andBaden-Württemberg. In the typical cultivation areas of Mid and Southern Bavaria (the ruraldistricts of Erding, Rottal-Inn, Landshut) and the area enclosed in the Rhine valley up to60% of arable land is cultivated with maize (ZSCHEISCHLER 1990).In the North-West-regions of Germany with high levels of livestock, maize for silage andCCM are essential components of the feed-rations for cows and pigs. Grain maize is used forpoultry forage. In the district of Weser-Ems more than 30% of the arable land is cultivatedwith maize (CHAMBER OF AGRICULTURE WESER-EMS 1998a). In intensive livestockfarms, ear maize is grown as an alternative to grain maize, relieving the farmers of the highcosts of drying. This particular harvest and preservation technique also makes the productionof profitable forage with maize possible in the cooler regions of Germany.The cultivation of maize for silage plays a large role in forage-growing farms. Maize forsilage is a valuable, high energy, basic forage and cattle seem to enjoy it so that forage intakeis high. Protein rich basic forage rations (with grass silage) in grassland-farms can becomplemented with maize-silage. The maize-silage increases the calorific value of the forageand ruminants then use the proteins more effectively. Also the quality of the basic forageitself increases and a better basic forage leads to higher livestock productivity and thepurchase of forage concentrates can be reduced. These benefits are additional to those ofhigher productivity per acre and the improved nutrient acquisition (particularly for farmyardmanure). The operational nitrogen balance of a farm can be improved by cultivating maize.In organic agriculture, maize for silage-cultivation still plays a minor role although theproductivity and the energy-content of the forage plant are topics of interest (GERMEIER1997). Since 1990, the arable land growing organic maize for silage amounts to less than 2%of all the land used for organic agriculture. Over the same time period, conventional farmsgrew maize for silage on 13% of their fields (FEDERAL GOVERNMENT 1990-1998).• data for the maize-cultivationIn order to give an overview of the status of maize production in agriculture the standardmarginal contributions are presented in Table 1. It should be remembered that a subsidy of443 to 797 DM/ha (1999) is paid for maize, depending on the federal state and region.

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XWLOL]DWLRQ�IRUP FURS�\LHOG JURVV�\LHOG YDULDEOH�FRVWV part -tonnes/ha without subsidy total seedes fertilizer weed control machines other AGMC

JUDLQ�PDL]H��6RXWK�)5*� 9 2160 1730 274 272 270 515 399 ��PDL]H�IRU�VLODJH��1RUWK�)5*� 45 2250* 1716 281 421 269 615 130 ��FRUQ�FRE�PL[��1RUWK�)5*� 12,5 2000** 1636 269 280 250 767 70 ��for comparison

ZLQWHU�ZKHDW��6RXWK�)5*� 7,5 1800 1148 130 260 271 427 60 ��WULWLFDOH��1RUWK�)5*� 6,5 1495 997 125 239 163 420 50 ��

assumtion: * value of maize silage = 50 DM/t x 45 = 2250 DM AGMC = average gross marginal contribution ** value of corn cob mix = 160 DM/t x 12,5 = 2000 DM

sources: Chamber of Agriculture Hannover 1999, KTBL average gross marginal contribution 1997/98

1.4 Agronomy bases of the maize-cultivation

Maize is very self-sufficient and therefore it can be grown as a monoculture. Its demand forwarmth during germination and early development (frost-sensitivity) leads to a late sowingfrom the end of April until mid-May, depending on the region. The 311 maize varietieswhich are officially recognised in Germany (1999) are adapted to local climatic conditions.

7DEOH� �� &ODVVLILFDWLRQ� RI� 0DL]H� YDULHWLHV� LQ� 0DWXULW\� (source: GERMAN MAIZE-COMMITTEE E.V. 1999)

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early until 220 14,0-15,0 °C

middle-early 230-250 15,0-15,5 °C

middle-late 260-290 15,6-16,4 °C

late 300-350 16,5-17,4 °C

* Ripeness-number approximately corresponds to the FAO-number

The maize hybrids are divided into maturity-groups, for both silage and grain use (Table 2).The ripeness number for silage is based on the ripening behaviour of the entire plant and theripeness number for grain only takes into account the maize ear.Maize grows, like potatoes and sugar beets, as a row-culture. Depending on the harvestingtechnology and its use, the distance between the rows is normally 75 cm and the populationdensity 9-13 plants/m2. If no mechanical weed control takes place, the distance between therows can be reduced to 30 cm. This increases the ability of the plants to exploit nutrients(CHAMBER OF AGRICULTURE WESER-EMS 1999), although appropriate sowing-techniques and a row-independent harvesting technology must be used. Harvesting isnormally contacted out.The cultivation of maize causes soil erosion in some regions of Germany. This occursmainly on hillside land with easily eroded soil material. The risk of soil erosion is greater inspring because maize is grown in rows and covers the ground late (LÜTKE ENTRUP &ZERHUSEN 1992). To protect the soil and to redevelop old neglected deposits of toxicwaste the Federal Soil Protection Law of 1998 (SOIL PROTECTION LAW 1998) shouldreduce erosion where it is avoidable with the help of suitable measures (FEDERALMINISTRY OF AGRICULTURE 1999).Despite the relatively high water use efficiency (3,3 g Dry Matter/ 1 kg water), the waterdemand of maize is considerably on the basis of the high output. In order to avoid yieldlosses, the water-demand should be especially catered for during June and July. In the classicdry areas of East and Central Germany as well as at Upper Rhine valley and in the water


catchment area of the Eifel, considerable shortfalls can occur in the water supply of theplants. In order to supply the high water need some farmers irrigate their maize.Maize is harvested in the autumn and late-autumn (September-December). Large, heavyharvesters to harvest and chop the maize for silage are used. Fair-weather is required forharvesting which is different than, for example, sugar beet. Over the last few years "staygreen" varieties of maize for silage have been used which extend the time for an optimalharvest and a high silage quality is possible and soil compaction can be avoided. Primarilyfarmers grow winter wheat which is adopted to late sowing as the following crop in arotation, if maize is not grown again (LÜTKE ENTRUP & ZERHUSEN 1992).

1.5 Fertilization and plant-protection in maize cultivation

• IHUWLOL]DWLRQThe European limit for nitrate in drinking water (EC-nitrate-guideline of 1991) was put intopractice in Germany in 1996. The German government implemented an ordinance for theprinciples of good technical practice for fertilization in agriculture (FERTILIZATIONORDINANCE 1996). This fertilization ordinance regulates the application of fertilizers,restricts times for the use of semi-liquid manure, compares nutrients and establishes a duty torecord fertilization for the first time on a national basis. It also lays down a maximumamount of manure which can be spread (maximum average content of 170 kg N/ha for eachagricultural enterprise). Concrete limits for mineral fertilizers, however, are not given in theordinance, nor are maximum levels of fertilization per acre for certain cultures (OSWALD1998). This ordinance is interpreted further by the individual governments of each federalstate.In contrast to other grain-types, maize has a period of especially intensive growth after aslow initial development. For this reason, plant-available nutrients (mainly phosphate) areplaced near the seedling during planting (underground fertilization). Maize is very effectiveat using mineralized nitrogen from manure because of its long vegetation time, which lastsuntil autumn (AUFHAMMER 1988).The following statements are based on official guidelines with respect to fertilization:1LWURJHQ: For an exact calculation of the N-fertilizer requirement, the mineral-nitrogen-

content of the soil between the 6 and 8 leaf stage of the maize is measured. Only when themaize-plants are so far developed they can incorporate nutrients in considerablequantities. The difference between the measured nitrogen level and what is appropriateshould be made up with mineral and/or manure fertilizer. The appropriate level ofnitrogen is determined on a regional basis (180-200 kg N/ha) and depends on theexpected profits.

3KRVSKRUXV: It promotes the initial development, bloom and fruit-formation as well asstarch-storage. Dependent on the variety of maize grown, 40 – 50 kg/ha of phosphorusper crop is removed and should be replaced by fertilization.

3RWDVVLXP: Beside the positive influence on the water supply, potassium promotes thedevelopment of mass in the shooting phase and increases the steadiness of the maize.Also the resistance of the plant against illnesses and pests increases. Maize has a highpotassium requirement. The removal of potassium from the soil depends on the use of themaize and varies from 140 to 250 kg K/ha.

0DJQHVLXP: The demand of maize for magnesium is comparatively low and is met bynormal fertilization with manure in livestock farms (grain maize removes 20 kg Mg/haand silage maize 40 kg Mg/ha).

These figures do not necessarily reflect what happens in practice. It can be assumed thatmanure is used at high levels as well as other fertilizers. Maize tolerates a high level of


fertilizer and in intensive livestock farms large quantities of semi-liquid manure need to bedisposed of.

• SODQW�SURWHFWLRQThe use of pesticides is regulated by the nationally applicable ’law to protect crops’, short:plant protection law (PLANT PROTECTION LAW 1998) which came into effect on 14.May 1998. In water protection areas some pesticides are forbidden (PLANT-PROTECTION-APPLICATION-ORDINANCE 1997). Pesticides which are allowed todayfor the cultivation of maize are not yet included in the list of forbidden pesticides.

Direct plant protection precautions for maize are, essentially, aimed at weed control. In theSouthern, and therefore warmer regions of Germany, the fight against the European cornborer (Ostrina nubilalis) is important. As a preventative measure, the harvest residuals arecrushed and deeply ploughed in. Two biological measures are available to combat the cornborer. The use of slip-wasps (Trichogramma) and the spraying of a bacillus thuringiensispreparation are practicable. Insecticides are less important. Fungicides are not applied duringthe cultivation of maize. Coating the seed to prevent the development of the fruit fly larvae(Oscinella frit) is standard practice. Maize does not compete well with weeds in its earlydevelopment stage and this has meant that there is an economic necessity to deal with them.&KHPLFDO�ZHHG�FRQWURO: After the discontinuation of Atrazin (application was prohibited in

Germany from 1991) new herbicides and mixtures were developed. They are used beforesowing, before or after plant shooting. In some regions of Germany, herbicide-resistanceshave appeared with intensive maize cultivation. Some weeds are very difficult toeliminate. In the North of Germany: cock’s-foot grass ((FKLQRFKORD�FUXV�JDOOL), hairycrabgrass ('LJLWDULD�VDQJXLQDOLV), and in South Germany: millets (6HWDULD�JODXFD�YLULGLV), fat hen (&KHQRSRGLXP�DOEXP) and black nightshade (6RODQXP�QLJUXP) areserious weeds.

0HFKDQLFDO�ZHHG�FRQWURO: farmers can work between the rows with various types ofmechanical hoes. Up until harvesting the use of the blind-currycomb is also possible. InGermany, mechanical weed control is used only to a minor extent because agrochemicalsare cheaper.

A combination of chemical and mechanical weed control can be implemented by bandspraying. This helps to reduce the use of pesticides, but only a few farmers use this technique(LÜTKE ENTRUP & ZERHUSEN 1992).


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In the state of Lower Saxony, the cultivation of maize has become very important over thelast few decades, particularly for forage-production. The land area used for silage maizeincreased up until the middle of the 1980s to 200,000 ha (figure 5). The breeding of earlymaize varieties and developments in harvesting technology have led to an increase in theland given over to maize since the beginning of the 1980s. The acreage of grassland, whichis very significant for the natural environment, water protection and for producing forage onthe farms, has continuously decreased over the last 30 years. Today maize is often cultivatedon former grassland. If wet periods frequently occur over the winter, maize can be sown latein comparison to other crops.

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DFUHDJ

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Grain maize(CCM)

Maize for Silage

Permanent Grassland

(1999 preliminary)

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In 1998, 60% of the total area used for the cultivation of maize in Lower Saxony was inWeser-Ems region, although it is only 31% of the farmland of Lower Saxony. Thishighlights the strong concentration of the maize in this region.

2.1 Description of Weser-Ems

The Weser-Ems district is in the west of Lower Saxony and borders the Netherlands (figure6). It possesses an agricultural chamber of its own, based in Oldenburg. Weser-Ems includesthe towns of Delmenhorst, Emden, Oldenburg, Osnabruck and Wilhelmshaven and 12 otherrural districts (table 3 ).


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• climate - and soil circumstancesA moderate maritime climate prevails in Weser-Ems. The average precipitation is 810 mmper year. Inland, it rains between 650 and 700 mm per year. The average temperature is to8.5°C. From May until September, which is vital for the growing of maize, the averagetemperature is approximately 15°C. Conditions for the silage maize cultivation and CCM aregood. The production of grain maize is only possible with early maturing varieties. Anenergy-intensive drying of the maize-grains is normally necessary because the maize has awater content of 30-35%. Some farmers use propion-acid for a conservation.One finds the following soil circumstances in the Weser-Ems (figure 7): Marsh grounds ofdifferent types have been formed in the coastal-area from young sea sediments. Furtherinside of Weser-Ems on the post ice-age grounds, soil has been formed over pleistocenesands and old moraines. There are extensive moor areas nearby which transforms to meadowaround the wider river valleys. The grounds in the most southern part of the area havedeveloped from loess-sediments, although in Weser-Ems this area is small. Podzols, podzol-brown-earths, Podzol-Para-brown-earth and moors are among the frequent inland soil-types.


Soil-types are silt, clay and humus sands. The sandy soils have a relatively low mechanicalfiltering ability and middle to high water permeability. There is a relatively high potential forfertilizers and pesticides to be carried into the groundwater by rain.

• structure of agricultureDairy farms are mainly in the coastal rural districts of Aurich, Wittmund and Wesermarsch,where there is a high proportion of grassland. In these forage-growing farms, the little arableland is frequently used every year to produce silage maize. The share of maize is low inrelation to the agricultural land (incl. grassland), but it is high in relation to the arable land(table 3). In the rural districts Vechta, Oldenburg, Cloppenburg and Emsland grassland isless important. Here, intensive livestock farms with pig and/or poultry have been established.

red: Coastal-marsh

yellow: Sandy soil from thepost ice-age

green: humus-moor soil

brown: brown and parabrown- earth on loess sediments

source: FEDERAL-OFFICE FOR SOIL-RESEARCH OF LOWER SAXONY

)LJXUH��6RLO�PDS�RI�:HVHU�(PV


The size of farms in the Weser-Ems region is lower then the average for Lower Saxony.Most farms have a size of 30-50 ha agricultural land (table 4). There is a below averagenumber of farms with more than 50 ha of land in the Weser-Ems region. This is reflected bythe importance of livestock production which is less dependent on the size of the farms.7DEOH��$JULFXOWXUDO�EXVLQHVVHV�JURXSHG�E\�TXDQWLW\�RI� WKH�DJULFXOWXUDO� XVHG� ODQG��(source: STATISTICAL FEDERAL-DEPARTMENT)

:HVHU�(PV /RZHU�6D[RQ\

size farms farms

from... to under.... ha number sharein %

number sharein %

1 - 2 3.836 11,0 8.887 11,2

2 - 5 4.559 13,1 10.468 13,2

5 - 10 3.977 11,4 8.506 10,7

7DEOH��6L]HV�RI�ILHOG�DQG�JUDVVODQGV�DQG�SURSRUWLRQ�RI�ODQG�XQGHU�PDL]H�LQ�WKHUXUDO�GLVWULFWV�RI�:HVHU�(PV��(source: LOWER SAXONY DEPARTMENT FORSTATISTICS 1999)

rural districts

farmlandin ha

therefromgrassland

in ha

therefromarable land

in ha in % of farmland

maize-shareof the arable

land

Ammerland 44.488 31.923 15.041 32% 51%

Aurich 85.367 54.672 31.100 36% 14%

Cloppenburg 97.778 21.655 76.519 78% 37%

Emsland 168.767 25.792 143.206

85%

32%

Friesland 43.576 32.940 10.774 25% 26%

Graf.

Bentheim

60.906 18.644 42.369 69% 42%

Leer 71.334 59.742 11.715 16% 42%

Oldenburg 67.145 21.899 45.496 68% 27%

Osnabrück 124.023 29.517 95.195 76% 27%

Vechta 66.458 10.639 56.124 84% 33%

Wesermarsch 61.362 59.009 2.412 4% 57%

Wittmund 47.246 33.744 13.581 29% 24%

total 943.708 400.176 543.532

58%

32%


10 - 15 2.586 7,4 5.504 6,9

15 - 20 2.207 6,3 4.710 5,9

20 - 30 4.419 12,7 8.304 10,4

30 - 50 7.215 20,7 13.797 17,4

50 - 100 5.372 15,4 14.927 18,8

100 and more 710 2,0 4.369 5,5

total 34.881 100 79.472 100

2.2 Land used for the cultivation of maize in Weser-Ems

13,6%

41,6%

23,6%

26,0%

56,9%

50,3%

22,9%

27,6%

17,8%

18,5%

22,7%

33,5%

23,9%

2,8%

8,3%

12,9%

5,5%

4,5%

5,3%

5,3%

2,5%

3,4%

5,0%

2,9%

2,7%

0,4%

0,1%

0,1%

1,3%

1,6%

0,4%

0,1%

0,1%

0% 10% 20% 30% 40% 50% 60%

Aurich

Leer

Wittmund

Friesland

Wesermarsch

Ammerland

Oldenburg

Cloppenburg

Vechta

Osnabrück

Emsland

Gr.Bentheim

Weser-Ems

Corn Cob Mix (% arable land)

Grain Maize (% arable land)

Maize for Silage (% arable land)

Rural Districts:

)LJXUH��$UDEOH�/DQG�XVHG�IRU�WKH�FXOWLYDWLRQ�RI�PDL]H�LQ�WKH�:HVHU�(PV�LQ��VXEGLYLGHG�E\�XWLOL]DWLRQ�IRUP�(Source: LOWER SAXONY DEPARTMENT FORSTATISTICS 1999)

Figure 8 shows that the predominant regions for maize as grain maize and CCM are Vechta,Cloppenburg, Emsland, Osnabruck and Bentheim where these crops are grown to aconsiderable extent. These rural districts show with 70-85% the highest proportion ofagricultural land which is arable (compare table 3). In the grassland-regions (rural coastaldistricts), silage maize is grown almost exclusively as a high energy basic forage which isimportant for cattle. The high quality of silage maize leads to its extended use. On heavymarshes, timely sowing is not always possible and the harvest is difficult. Higherprecipitations (up to 900 mm) and lower summer-temperatures in the coastal-situationsretard the ripening of the maize.

2.3 Yield of maize

• data from survey of the Lower Saxony department for statistics


Figure 9 shows the average yields achieved with silage and grain maize for 1994-98 in therural districts of Weser-Ems.

4

5

6

7

8

Aur

ich

Leer

Witt

mun

d

Frie

slan

d

Wes

erm

arsc

h

Am

mer

land

Old

enbu

rg

Clo

ppen

burg

Vec

hta

Osn

abrü

ck

Em

slan

d

Gr.

Ben

thei

m

Wes

er-E

ms

Low

er S

axon

y

25

30

35

40

45

Grain Maize incl. CCM 1994-98

Maize for Silage 1994-98

Maize for Silaget/ha green material

Grain maizet/ha dry material (14% water)

)LJXUH��$YHUDJH�\LHOGV�RI�JUDLQ�PDL]H�DQG�VLODJH�PDL]H�LQ�WKH�UXUDO�GLVWULFWV�:HVHU�(PV��(source: LOWER SAXONY DEPARTMENT FOR STATISTICS 1995-99)

The average yield-level in Weser-Ems corresponds closely to the Lower Saxony stateaverage. Between the individual rural districts, however clear differences in yield exist withboth maize types. These differences amount to about 10 dt/ha grain with the grain maize andabout 58 dt/ha green-mass-yield with the silage maize. In the coastal-regions, the harvests ofgrain maize tend to be lower than in the inland (compare the left half of figure 4, the ruraldistricts from Aurich to Wesermarsch). The yields of silage maize show no region-specificvariation.

• Yield data of the Weser-Ems agricultural chamberA more elaborate illustration of the yield, and quality parameters of silage, and grain maizein the Weser-Ems from 1996 to 98 is shown in table 5. The data were collected in theframework of trials of different varieties by the Weser-Ems agricultural chamber. It shouldbe noted that the results were achieved under optimum production and technical conditions.The results of yield and quality correspond to the upper level of results from real farms. Dueto climatic conditions only early and middle early varieties were used.Average results for 1996-98, show that the early silage maize varieties exhibitedapproximately 10% better dry matter ripening behaviour, and approximately 10% higherstarch content, than the middle-early kinds. However small yield reductions in terms of dry-mass were noticeable for the early varieties compared to the middle-early varieties.Although the differences in yield for grain maize between the early and middle-earlyvarieties for grain maize were very small, the early varieties had a higher dry matter contentand so are preferred on farms.

7DEOH��$YHUDJH�\LHOGV�IRU�VLODJH�DQG�JUDLQ�PDL]H�LQ�:HVHU�(PV��UHVXOWV�RI�WKHYDULHWDO�WULDO�RI�WKH�IHGHUDO�VWDWH��YDOXHV�FRUUHVSRQG�WR�WKH�DYHUDJH�RI�EORFNV


(Source: AGRICULTURE-CHAMBER WESER-EMS 1999)

Maturity-group early Maturity-group middle-early(old FAO-number until 220) (old FAO-number 230-250)

0DL]H�IRU�6LODJH 1996 1997 1998 96-98 1996 1997 1998 96-98dry matter t/ha 15,8 20,2 17,6 17,9 15,6 21,3 18,3 18,4dry matter content % 32,0 37,7 34,3 34,3 28,4 35,5 31,1 31,7energy-yield MJNEL/ha 96394 129195 112811 112800 96349 135444 115978 115146net energy content MJ NEL/ kg dm 6,1 6,4 6,4 6,3 6,0 6,4 6,3 6,2starch yield t/ha 4,39 6,69 5,91 5,66 3,82 6,76 5,60 5,39starch content % in dm 27,9 33,2 33,8 31,6 24,4 31,8 30,7 29,0

*UDLQ�PDL]Hgrain yield t/ha 8,44 10,8 10,33 9,86 8,76 11,19 10,34 10,1dry matter content of grain** % 61,7 69,2 64,1 65 59,8 67,5 60,6 62,6

dm = dry matter * grain yield at 86% dry matter in t/ha ** at the time of harvest

2.4 Livestock production and corresponding manure quantities in the rural districts

In some rural districts of Weser-Ems a strong concentration of the livestock population canbe seen (SCHÜRMANN 1998). The highest livestock densities occur in the districts ofVechta and Cloppenburg. Cows, pigs and poultry are kept here in high densities, see table 6.In Germany, cattle need to be housed from the end of November until the middle of April instables because of the climatic conditions. Often cows are housed the whole year. Thisimplicate high amounts of manure, which have to be stored and later spread out on the land.A very high density of maize-cultivation takes place in these areas. In some forage-growingfarms of the rural coastal districts very intensive maize-cultivation occurs. In these areas thelimited arable land is used almost exclusively to cultivate maize for silage, i.e. maize isgrown as monoculture. Fertilization of maize is mainly achieved with semi-liquid manurefrom cattle (quantities of 40-50 m³/ha).

7DEOH��'HQVLW\�RI�OLYHVWRFN�LQ�PDQXUH�XQLWV ��'(��SHU�KD�LQ�WKH�UXUDO�GLVWULFWV�RI:HVHU�(PV��(Source: LOWER SAXONY DEPARTMENT FOR STATISTICS 1996)

Rural district Livestock-density manure-

cattle pigs poultry total ** fertilizer

DE/ha LF DE/ha LF DE/ha LF DE/ ha LF kg N/ha

Ammerland 0,91 0,13 0,03 1,11 89

Aurich 0,68 0,07 0,01 0,79 64

Cloppenburg 0,80 0,78 0,42 2,02 162

Emsland 0,58 0,53 0,17 1,30 104

Friesland 0,86 0,05 0,01 0,96 77

Graf. Bentheim 0,83 0,50 0,23 1,59 127

Leer 0,88 0,03 0 0,94 75

Oldenburg 0,63 0,40 0,25 1,32 105

Osnabrück 0,54 0,54 0,29 1,41 113


Vechta 0,74 1,04 1,4 3,21 257

Wesermarsch 1,00 0,01 0 1,07 86

Wittmund 0,84 0,06 0 0,93 74

Weser-Ems total 0,73 0,40 0,24 1,41 113

Lower Saxony 0,49 0,23 0,11 0,86 69

* 1 manure unit (DE) corresponds to farmyard manure of 80 kg N from animal production** incl. horses and sheep LF = farmland

In the rural district Vechta, the produced manure can not properly be utilized on the existingagricultural land. The maximum allowable quantity stipulated for spreading within anagricultural enterprise is 170 kg N/ha. Therefore excess must be exported into theneighbouring districts, partly with a “semi-liquid manure stock exchange”. This entailsadditional costs for transportation and spreading-expenses for the livestock farmers.

2.5 Effects on the environment and avoidance-strategies

In some regions of Weser-Ems, the nitrate-values measured in the groundwater aresometimes considerably higher than the EC-drinking water-limit of 50 mg nitrate per litre.The rural districts involved are Oldenburg, Cloppenburg, Vechta and Bentheim in whichapproximately one third of the wells in the network of controlled water supplies shownitrate-values of 50-100 mg Nitrate/l and above (FEDERAL OFFICE FOR ECOLOGY OFLOWER SAXONY 1997). Exactly how the cultivation of maize causes this is not preciselycalculable. This is mainly because the number of samples which have been taken overseveral years is small. Most field attempts restrict themselves to calculating leaching ofnitrate by using nutrient-balances or soil-examinations. The calculation of simple nitrogenbalances per farm or better per field is easy done and helps to detect an incorrect fertilization(GÄTH 1997) The samples taken by LORENZ (1997, 1992) in Weser-Ems show that thescale of the nitrogen leaching cannot be derived from simple nitrogen balances, althoughmeasurements of soil nitrate do allow for an indication of the potential of leaching of nitrate.The areas concerned, Oldenburg, Cloppenburg, Vechta and Bentheim, produce only slightlyhigher values of maize than the average for the Weser-Ems, although they do have a higheragricultural acreage and a clearly higher farmyard manure-amount per ha, see table 6.The cultivation of maize need not lead to elevated nitrate-displacements in principle. Moreimportant is the question of optimal fertilization. The cause of the groundwater problems inthe four livestock intensive rural districts is therefore seen predominantly in areas with ahigh level of manure spreading takes place. Maize, which tolerates an over supply of semi-liquid manure without suffering damage, primarily functions as a "waste disposal-plant " forsurplus farmyard manure. In practice, 40-50 m³ per hectare of semi-liquid manure from cowsor pigs is spread on maize fields. Additional underground fertilization with a mixture ofdiammoniumphosphate and calcium ammonium nitrate at 1:1 (approximately 1.5 dt/ha) is astandard measure. The result is fertilization of maize at 180 - 220 kg N/ha with semi-liquidcattle manure and from 204-276 kg N/ha with semi-liquid pig manure. In practice, thenitrogen extraction of maize for the average-yield in the Weser-Ems is approximately 150-200 kg N/ha. This highlights the difference between the applied nitrogen and what is used bythe crop (GÄTH 1997). Manuring with semi-liquid pig manure, especially, leads to surplusnitrogen.


Another problem is the enrichment of the soil with phosphate. According to the statisticsfrom soil examinations by the Agricultural Lab Oldenburg, in 1981 only 11% of soils in theWeser-Ems showed a very high phosphate content (>30 mg P2O5/100g soil). By 1994 thishad risen to 45%. Over fertilisation with manure is the cause of this development (before allsemi-liquid manure is applied). The farmers prefer the fertilization of maize with manure.Additionally, underground fertilization with phosphate-containing fertilizers is applied tomaize (CHAMBER OF AGRICULTURE WESER-EMS WESER-EMS 1998b)The development and the implementation of environmentally compatible productionstrategies for maize cultivation in the Weser-Ems happens on several levels:· realization of cultivation tests especially in water-protection and water-priority-areas· cultivation consultation especially in water-protection and water-priority-areas· voluntary cultivation-agreements in water-protection and water-priority-areas

&XOWLYDWLRQ�WHVWVIn the Weser-Ems studies are currently being undertaken relating to the cultivation of maize.The main themes of these studies are questions about the effects of different variations oforganic and mineral nitrogen fertilization, underground fertilization, under seeding, previouscrops and row distances in view of soil-nitrate development, nitrate-leaching, yield andquality of the harvest crops. Consequently, the following tendencies have been noticed onthe basis of the short running time of the trials (at most 4 years):• There is a close connection between the level of the nitrogen fertilization for maize and

the residual soil-nitrate values remaining in the soil after the harvest. Nitrogen fertilisationabove the optimal nitrogen supply, especially, leads to a clear increase in the risk ofnitrogen being leached from the soil. This risk is less if the land is used as a frequently cutmeadow or culivated with winter-rye or winter-barley. (BENKE ET AL. 1999)

• Between September and December the soil nitrate content after the cultivation of maize isclearly higher than that after winter-grain (CHAMBER OF AGRICULTURE WESER-EMS 1998 b)

• Sowing grasses into established maize stands (maize plants 20 cm high) can reduce theamount of residual nitrate in the soil at the end of the vegetation period. Undersownmaize does not necessarily reduce maize yield as long as the seeding of the grass is notdone to early. The early sowing of Italian ryegrass, especially, can clearly reduce theresidual soil nitrate level. (CHAMBER OF AGRICULTURE WESER-EMS 1998 b)

• Managing the soil with a plough leads to a higher soil nitrate level than with a cultivator.(CHAMBER OF AGRICULTURE WESER-EMS 1998 b).

• The scale of nitrate leaching depends, very much, on the annual weather, and,particularly, the weather circumstances in the winter (BENKE ET AL. 1999).

&RQVXOWDWLRQCurrent information about the cultivation of maize is available to the farmers throughprofessional journals, regional weekly papers and reports/minutes of the agriculture-chamberWeser-Ems. Farmers, who work in water protection- and water priority areas (approximately3700 farmers), receive a specific advisory services (in addition to the regular service), thattakes place by order of the water company. In the district Weser-Ems 19 water consultantsare responsible for 66 water-protection and water-priority areas. These areas have an acreageof 120.000 ha; approximately 70.000 ha of them are used for agriculture. Besides the group-consultation (inspections, viewing demonstration fields, general information events) and theinformation from briefs and newsletters, the individual farm should be adviced.

9ROXQWDU\�DJUHHPHQWV


7DEOH��6HOHFWLRQ�RI�YROXQWDU\�DJUHHPHQWV�IRU�WKH�FXOWLYDWLRQ�RI�PDL]H�FXOWLYDWLRQ�LQZDWHU�SURWHFWLRQ�DUHDV�LQ�WKH�GLVWULFW�:HVHU�(PV�(Source: DISTRICT-GOVERNMENTWESER-EMS 1999)

PHDVXUHV LPSRVWV SD\PHQW

planning of fertilization withassessment of farmyard manure

implementation of the measures 25 DM/ha

spreading of semi-liquid manure withspecial technology

spreading in the sprouting plant cover,working in of the semi-liquid manure

2 DM/m³ for max.30 m³/ha

underseeding sowing with driller until maize is 50 cm 200 DM/ha

combination heel/ band spraying Weed control in maize field with heel incombination with a band spraying

80 DM/ha

catch crop cultivation before maize no legumes, ploughing up earliest 4 weeks beforeseeding; when rape was the previous crop, nofertilization

100 - 150 DM/ha

installation of demonstrations-trials 300 DM + x

building of storage for semi-liquidmanure

at least 6 months storage 80 DM/m³


In water-protection and water-priority-areas farmers can commit themselves within the scopeof voluntary agreements to undertake certain styles of management or cultivation-measures,which serve to protect the water. They receive financial support for this (table 7).

Also, agreements can be adjusted to a farm’s specific situation in cooperation with the waterconsultant. The voluntary agreements allow farmers some advantage for implementationwater sparing measures which would entail economic disadvantages if there were nofinancial rewards. In 1998, 3.300 voluntary agreements were completed in the Weser-Ems(CHAMBER OF AGRICULTURE WESER-EMS 1999).

6XFFHVV�DQG�EHQHILWReducing the leaching of nitrates is a long-term task. In water protection areas a moreappropriate treatment of the environment can be made practice. The primary motivatingforce for improved practices are the financial incentives, included in the voluntaryagreements.However, is not clear if these agreements are enough to maintain or improve the waterquality in the long term.In certain areas (above all those with permeable sandy soils), drastic measures are certainlyneeded in order to protect the groundwater on a long-term basis. Improved fertilizationtechniques could contribute to reducing leaching so that plants absorb a higher proportion ofthe plant available nutrients, including nitrates.Furthermore it should be remembered that the voluntary agreements are only effective inwater protection areas which are set up on a regional basis. In other regions, where noprotection has been established, improper plant production (primarily inappropriatefertilization management) negatively effects the groundwater.Maize tolerates very high quantities of manure. For this reason the fertilizer-quantity spreadon maize fields either should be regulated or the cultivation of maize itself has to be madeunattractive by political measures, like for example by reducing profits or subsidies.


�� (QYLURQPHQWDOO\�FRPSDWLEOH�FXOWLYDWLRQ�RI�PDL]H

Since the beginning of the eighties, measures for the environmentally compatible cultivationof maize have been tested and specifically developed from the points of view of the soil andprotecting the water. Their effectiveness with respect to environmental goals is different anddepends on the location. Individual measures or complex cultivation strategies intervenes indifferent ways and to differing degrees in operational and agrarian structural contexts. Andfinally depends on the willingness of the farmers to put environmentally compatible maize-cultivation-systems into the practice.

�� 0HDVXUHV�IRU�DQ�HQYLURQPHQWDOO\�FRPSDWLEOH�FXOWLYDWLRQ�RI�PDL]H

The procedures of an environmentally compatible cultivation of maize discussed in thefollowing text can be applied generally or targeted to individual situations. They also can becombined and integrated into environmentally compatible production systems. Someprocedures may be impractical in some locations. For example, the mechanical weed controlcan be difficult on humid locations; in dry-areas, the natural water-balance restricts the useof underseeding and catch crops.

• ZHHG�FRQWUROToday, a new generation of herbicides which are less dangerous to eluvium endangered areavailable for the cultivation of maize.The use of herbicides can be restricted by the use of time limits (permitted periods of timefor its application). Young maize-plants are especially sensitive to competition between the 4and 6-leaf-stage. Before and after this time, weeds can be tolerated to a greater degree. Laterthe maize-plants shade the ground so intensively that the growth of weeds is hindered.(AMMON & IRLA 1996)Row culture offers the possibility of mechanical weed control.A combination of chemical control in the row (band spraying) and mechanical controlbetween the rows increases the success of weed control.

• IHUWLOL]DWLRQThe prerequisite for appropriate fertilization of maize is an assessment of the nutrient contentin the farm manure.On top of the corresponding requirement fertilizer quantity, the time of spreading also playsan important role for a proper plant nutrition. Above all, farm manure should be applied sothat the offered nitrogen can be absorbed by the plants and does not lead to a burden on theenvironment. With the help of a special technique (band spreading), it is possible to applythe semi-liquid manure near the surface by the growing maize. For the precise recording ofquantitative fertilizer requirements of the maize, several parameters should be considered(LÜTKE 1996, LAURENZ 1996):- the nitrogen requirement of the maize according to yield expectation, in line with

controlled trials in the region (estimate)- the nitrogen supply of the soil at the beginning of the main growth period of maize (late

Nmin-Method) (measurement)- the long-term nitrogen delivery from the soil according to ground type = estimation- the nitrogen delivery from harvest remains, catch crops and nitrogen fertilization from the

previous crop (estimation).If a higher quantity of semi-liquid manure accumulates on a livestock farm than can be usedon land given to maize (so that the fertilization of nitrogen is not higher than nitrogenextraction), then the manure should be distributed more evenly over the entire farm area.


This means, preferably, all crops should be fertilized with semi-liquid manure (ZERHUSEN-BLECHER & LÜTKE ENTRUP 1997). With a very high livestock density the semi-liquidmanure may need to be exported, the livestock numbers reduced or the area of the farmincreased.

• FURS�URWDWLRQ��FXOWLYDWLRQThe cultivation of catch crops, before maize is planted, primarily serves to cover the groundthrough the winter. Depending on the previous crop, the number of any hibernating catchcrops can be considerable. With conservation tillage it is often useful to kill the catch cropsand weeds with a non selective herbicide directly before the sowing of the maize.Catch crops planted after maize should guarantee the reception of remaining nutrients.Because of the relatively late harvest of maize in most of the cultivation-areas in Germany,the selection of maize varieties is restricted to a few types which require late seeding dates.The need of catch crops during their development can be catered for by sowing them as anunderseed in maize. Thereby a higher catch crop mass can still be achieved in comparison tostubble seed in the autumn. Under seeds can also consist of grasses and of legumes.The procedure "maize-meadow" was specifically developed in Switzerland for regionswhere many roughages are used and precipitation is sufficient (AMMON & GARIBAY1995). The maize is sown into an existing turf with the technique of rotary sowing. The grasscover between the rows is usually kept short with mechanical methods.In addition, the reduction of the maize share in a crop rotation should be regarded as animportant aspect with diverse environmentally relevant effects, above all if it isinterconnected with the introduction of other plant cultures.

• VRLO�PDQDJHPHQWWith conservation tillage , the seed is brought into a catch crop cover that has experiencedfrost over winter or was destroyed with a total herbicide.The minimum level of plant activity in a soil can be destroyed by long term fundamental soilmanagement (plough); therefore different soil management systems as well as special-machines have been developed.

�� (IIHFWLYHQHVV�ZLWK�FRQVLGHUDWLRQ�RI�HQYLURQPHQWDO�JRDOV

An environmentally compatible cultivation of maize should have the goal of reducing nitrateleaching and erosion of the soil, to prevent herbicide contamination of the groundwater andto increase the biodiversity. The measures of integrated weed control, management offertilization, crop rotation-formation and soil management clearly differ in theireffectiveness for the different environmental goals (table 8).

- decrease soil erosionTo maintain the soil and to conserve its fertility, the procedures of a reduced soilmanagement system (conservation tillage, minimum cultivation), under-seeding and inter-cropping make a necessary contribution. In addition, they can decrease the unfavourableeffects of a close maize rotation.According to the seeding time and growth-conditions, under-seeding can serve differentfunctions. Early under-seeds can fix a nitrogen surplus, which can appear during thesummer. While they achieve a certain erosion-protection in a short time, they mainlypromote the acceptability of the ground in the autumn. Late under-seeding can hold nutrientsin the system over the winter and maintain a ground-cover. Through the application ofconservation tillage procedures and non-turning soil management, up to 70% ground cover


can be reached. As little as 30-50% ground cover can considerably decrease drainage fromthe surface and the soil loss. (SOMMER & BRUNOTTE 1997)

- decrease nitrate leachingThe entry of nitrates into the groundwater can clearly be restricted by orienting the nitrogenfertilization towards the demand of the plant, the total soil nitrogen content and the actualdelivery of nitrogen. Classification numbers about the nitrogen extraction ascertained by theharvested material, soil-nitrate assessments and the inclusion of weather dates can be used -also like in the grain-cultivation - for a targeted, location-adapted fertilization of maize.Above all, the loss of surplus nitrogen in the autumn can be prevented by underseeding,which grow after the maize harvest as catch crops.In livestock farms, a considerable part of the accruing semi-liquid manure quantities areapplied to maize. Procedural solutions allow its use, in line with requirements, whichdecreases the level of nitrogen compounds and smells being released into the atmosphere.After spreading, up to 65% of the ammonium-nitrogen can be lost through gaseous release.Therefore, the semi-liquid manure should be incorporated into the soil immediately afterspreading or, in the case of manuring, a standing plant cover has to be spread close to thesurface with the help of a special technique (band spreading).

- prevent herbicide leachingThe measure to reduce the danger of herbicide leaching has been partially carried outthrough public regulations (prohibition of atrazin!). Consistent compliance with theseregulations and further regulations very directly effect the harmful potential of leachingherbicides (GUTSCHE 1997). The use of machine heels and time restrictions lead to areduction in the use of herbicides. Although this allows, at least temporarily, a higher levelof weed infestation it can lead to an increase in the biodiversity. Use of mechanical weed-control through hoeing is not possible in silt-rich, hilly terrain because of the high risk of soilerosion. Instead, chemical procedures can be applied in connection with reduced soilmanagement procedures.

- increase biodiversityIncreasing the rotation of the crops by reducing the proportion of maize, cultivation of catchcrops in narrow, close maize rotations, planting maize cover or tolerating weeds covering thespaces between the rows or at certain times (see above) increases the biodiversity in themaize fields and in the landscape. Reduced soil management techniques for the cultivation ofmaize have positive effects on the activity of the soil flora and fauna (soil organisms)(JÄGGLI ET AL. 1995).


7DEOH� �� (IIHFWLYHQHVV� RI� GLIIHUHQW� PHDVXUHV� RI� WKH� HQYLURQPHQWDOO\� FRPSDWLEOH� FXOWLYDWLRQ� RI� PDL]H� ZLWK� UHVSHFW� WR� FHUWDLQHQYLURQPHQWDO�JRDOV

Environmental goal

Measure decrease soilerosion

decrease nitrogenleaching

decrease herbicidecontamination

increasebiodiversity

Weed control• substitute herbicides which may leach o o ++ o• economic thresholds (time-limits) + o + o until +• combination band spraying, mechanical control – o ++ +• mechanical control – o +++ ++Fertilization• investigation of the nitrogen content of the manure o + o o• well timed organic and mineral fertilization

(based on the use of fertiliser by the plant cover)

o ++ o o

• late nitrate examination of the soil o ++ o o• distribution of organic manure (farm or farmland), o + until +++ o oCrop rotation / cultivation• catch crop cultivation before maize ++ o o +• catch crop cultivation after maize o ++ o +• under-seeding + ++ until +++ + ++• maize-meadow +++ +++ ++ ++• reduction in proportion of maize in the crop rotation ++ + until +++ – until + +Soil management• conservation tillage ++ o o until – o• minimal tillage +++ o – o

Effectiveness with respect to the environmental goal: + low ++ middle +++ high –negative o no effect


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In sections 3.1 and 3.2 the measures discussed for the decrease of the environmental burdenby the cultivation of maize make different demands of production techniques as well as theoperational assumptions. If these demands are not met, the measures cannot be realized. Therespective demands of the measures, their costs and effects on profit determine theiracceptance in agricultural practice. Generally it can be said that the less a measure costs andthe less negative influence the measure has on profit, the sooner it is accepted in the practice.In table 9 environment protecting cultivation measures are estimated with respect to theirtechnical production and yield effects and their acceptability by farmers and are shownschematically. These evaluations represent no solid, invariable measurements and, inindividual cases, cannot apply independently from local and operational realities.Altogether there are measures which can be put into practice easily without greaterconsequences for maize production and measures which do not cause a considerable changein practices of the farms. The effects of the measures on the structure of costs and profits canbe very different. Changes in herbicide application, on the whole, lead to higher costs, whilemachine costs and working times are reduced with soil management procedures. Mineralfertilizer can be saved by a more economic use of organic manure. Decisions need to be madewhether new special machines are purchased, or whether it is more favourable to have thework done by a private contractor. Farmers frequently do not have their own appliances formachine-hoeing, so, currently, they are still dependent on employing private contractorswhere postponements in time can occur. If the optimal time for hoe treatment is missed,reductions in yield are the consequence. This situation does not contribute to an increasingacceptance of mechanical weed control measures.Weed-hoe machines can be used well on dry locations. On rather humid grounds, therestriction in time of the optimal treatment-conditions leads to strong doubts. Moreoveroptimal weather and ground-structure and the absence of problematic weeds are prerequisitefor successful mechanical weed control. Used by itself mechanical weed control necessitatesthe timely use of special-machines, and can spill weeds between the maize plants. Ifmechanical weed control is combined with under-seeding, then the under-seedlings can beplanted relatively late into the maize cover, which had previously been hoed.

In border locations of the maize cultivated areas, conservation or minimum tillage can have adisadvantageous effect because of lower soil-temperatures. When methods to turn the soil areabandoned completely, root-spreading weeds need to be considered whose control normallynecessitates the use of a total herbicide. In order to prevent a one-sided development ofproblematic weeds by practising the method of minimum cultivation, crop changes should beincreased as a preventive measure (more diverse crop rotations, changes of summer andwinter crops).The introduction of catch crop cultivation before or after maize needs no special change in theproduction technology of the maize and puts no further demands on the farm. Favourableeffects of catch crop cultivation on soil qualities or the health of following crops has beenroughly estimated in a favourable light. At locations with a tendency of an early summerdryness, the need for water of the maize can be reduced by planting winter catch crops priorto the maize. Underseeding has two contrary risks; on the one hand the under seed can failwith unfavourable conditions for emergence (dryness), on the other hand, a well establishedand luxuriant development of the underseed can introduce yield influencing competition forthe maize. The cultivation of underseeds requires experience and skills in plant cultivationfrom the farmer (choice of plant species, date and method of seeding). The expansion of thecrop rotation and the reduction of the maize-share can have considerable consequences for thefarm, from the management of forage to livestock husbandry.


An improvement in the environmental compatibility of agricultural production proceduresmust not be inevitably interconnected with an escalation of expenses. For example, themethod of minimal soil cultivation implies a reduced intensity of cultivation. Since farmers, inline with the fertilizing regulations, have had to record dates of use of manure and bought-infertilizers, willingness has climbed to use the nutrient of the manure more economically ontheir farm. The saving of mineral fertilizers obviously has an effect on a farm’s results.

With the realization of an environmentally compatible and profit oriented cultivation ofmaize, conflicts between goals of environmental protection and economy in the cultivation ofmaize have to be managed in the context of each individual farm. The behaviour of farmmanagers is decided by legal, agrarian-political and location-specific basic conditions,personal attitudes, the level of training and information, the operational facts and, notultimately, by economic considerations.


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Measure Demands of the measure Effect on *) Acceptance #) ofthe measure

yield risk expenses to farmers

Weed control

• substitute herbicides which may leach information ο ο ↑ 1

• economic thresholds (time-limits) weed exaltation, information ο ↑ ο 2

• combination band spraying - mechanical control Special machines ο ο ↑ 2

• mechanical control Special machines ↓ ↑ ↑ 3

Fertilization

• investigation of the nitrogen content of the manure sampling and analysis ο ο ↑ 2• well timed organic and mineral fertilization (based on

the use of fertiliser by the plant cover)improved techniques for manure spreading ο ↑ ↑ 2

• Late nitrate examination of the soil sampling and analysis ο ο ↑ 2• distribution of organic manure (farm or farmland), band spreading technology for semi-liquid manure in

growing plants and distribution on the farmlandο ο ↓ - ↑ 1

• reducing of organic fertilization export of manure, expansion of the agricultural land,reduction in the livestock numbers

o o ↑ 3

Crop rotation / cultivation

• catch crop cultivation before maize expenditure for cultivation, increasing water demand,seed time for maize perhaps belated

ο ↑ ↑ 1-2

• catch crop cultivation after maize expenditure for cultivation, soil management / totalherbicide

ο ο ↑ 1-2

• under-seeding expenditure for cultivation ο ↑ ↑ 3• maize-meadow Changed cultivation technology, high water demand ↓ ↑ ↑ 3• reduction in proportion of maize in the crop rotation procurement of forage ο ο ↑ 3

Soil management

• conservation tillage special sowing technology, catch crop cultivation ο ο ↑ 2

• minimal tillage special technology for soil treatment and seed ο - ↓ ↑ ↑ 3

*) ο no one #) 1) high, measure can be introduced easily into practice↑ increase 2) middle, introduction necessitates additional advice↓ decrease 3) low, introduction necessitates financial incentive


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A first crucial step for the implementation of environmentally compatible maize-cultivationtechniques into agricultural practice is the consistent application of legal restrictions and theprinciples of proper agriculture (CHAMBER OF AGRICULTURE HANNOVER &WESER-EMS 1991). Despite diverse consultation and enlightenment activities in thescientific community, the agrarian administration and water management, many farmersretain their conventional production procedures, so a demand for action still exists. The soilprotection law and the fertilizing regulations prescribe soil preservation treatment proceduresand an environmentally compatible management of fertilization. Golden rules for thesuccessful maize cultivation like plow furrowing, high amounts of semi-liquid manure andthe use of Atrazin are no longer valid. The change in the basic legal conditions has led to anuncertainty of production in the farmers. In the following, a few individual examples frompractical experiences are briefly discussed.The different procedures of an environmentally compatible cultivation of maize havebecome accepted very differently in practice. On the one hand, this is related to thecomplexity of the location realities and the demands of the respective measure. On the otherhand, state-specific agrarian political basic conditions must be taken into account.While in the erosion endangered maize cultivating areas of Baden-Württemberg theconservation tillage of maize in catch crop cover which has suffered frost has alreadybecome standard (HUGGER 1997), farmers in Lower Saxony still clearly underestimate thedanger of erosion from the cultivation of maize in the lowlands and show little readiness toimplement improved cultivation methods for maize (LÜTKE ENTRUP et al.1995).The acceptance of mechanical weed control measures in the cultivation maize is still low.The procedures have been developed and tested, but the technology is expensive and theapplication of herbicides appears even more certain. The nationwide prohibition of applyingAtrazin in 1991 has already reduced the effects on ground and surface water from thisherbicide. Since then, numerous maize herbicides are available in diverse combinationswhich allow for a targeted use against individual weeds. The considerable rise in demand forconsultation offers a chance to test and to put into practice other weed regulation procedures.In almost all states, extensive production procedures in agriculture are promoted accordingto the ordinance (EEC) No. 2078/92. Overall it is about so-called relinquishment measures(fertilization, plant-protection) which are mainly employed by farms working with lowintensities in less productive locations (OSTERBURG ET AL. 1997). Measures likeherbicide relinquishment have not yet been able to establish themselves in the cultivation ofmaize, therefore only 2% of maize areas in Baden-Württemberg have seen these measurespromoted (HUGGER 1997). The large maize producing states, Baden-Württemberg,Bavaria, Brandenburg and Saxony, already promote targeted soil preservation measures likeland planting, the conservation tillage and under seeding. These are measures that can, on thebasis of land used, be integrated into an environmentally compatible maize productionsystem. (PLANKL 1996; OSTERBURG ET AL. 1997)With particular promotion programs and the creation of network projects in regional showfarms North Rhine-Westphalia has attempted to put scientific viewpoints of integrated agri-culture into the practice and to introduce them as examples (LÜTKE ENTRUP et al. 1992).In Lower Saxony, demonstrations have proved to be very effective by which measures ofenvironmentally friendly cultivation have been exhibited as examples on agricultural farms,so that the results can be seen as positive examples for a whole cultivation region. If thesepilot projects are combined with investment aids into new technology, well trained andinterested farmers change over time to environmental compatible production techniques.On basis of the laws controlling waterways, financial compensation for farmers and a specialconsultation service, the protection of water can be implemented and financed. From 1994 to


1996 in Lower Saxony over 13 million DM were spent on additional consultation in water-protection and water catchment areas (FEDERAL OFFICE FOR ECOLOGY OF LOWERSAXONY 1998). Catch crop cultivation and the use of special machines for the surfaceapplication (band spreading) of semi liquid manure, which are also applicable in thecultivation of maize, have been adopted on a wide basis. Underseeding or even changes incrop rotation are done only from a few farmers. (FEDERAL OFFICE FOR ECOLOGY OFLOWER SAXONY 1997)

In the Weser-Ems region the cultivation of maize is usually forbidden in water protectedareas nearby the fountain (BEVERBORG 1996). But more recent experience shows that thecultivation of maize can be integrated well into a water dependency program (FREDE &DABBERT 1998). For quite a time, the support of environmentally compatible maize-cultivation techniques has taken place through voluntary cooperation between watermanagement and agriculture which are oriented towards environmental indicators.Such packages of measures that are developed as common actions of all involved social andinterest groups can clearly be the most successful. Criteria for this are the multidisciplinarycooperation of the administration (water management, land use system, agriculture,landscape management) and the intensive consultation and dialogue with the farmers.

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In sections 3.1 to 3.4 measures were introduced and appraised for an environment savingcultivation of maize which has been examined and tested scientifically, and their applicationhave been established in practice. In agrarian research, one looks for further possibilities ofmore efficient and environmentally compatible cultivation. The following is an outline ofwhich technical improvements in production could attain importance in the medium term inthe practice of the cultivation of maize, as well as which innovations appear desirable.Newer implements for mechanical weed control try, with the help of atmospheric pressurecontrolled from the ground, to antagonize weeds between the rows. The procedure is not yetfully established, and suffers from restrictions in the ground condition and weather, like theother mechanical technologies currently available. The success of weed control betweenrows could, however, be clearly improved and this method could replace the band sprayingof herbicides. Although there is considerable scientific and practical experience of thermalprocedures of weed control, the high expense of the method raises questions of profitabilityespecially for fodder plant. This means that further developments of this technology need toaddress the cost factor.In recent years a dynamic development in the area of breeding herbicide resistant maizevarieties with the help of genetic engineering methods has taken place. Environmentalbenefits and environmental risks that could result from the introduction of herbicide resistantmaize are controversially discussed. Another point of criticism is the even stronger marketpower of the agricultural industry, if seed and herbicide are sold by the same company.Normally, a resistance against non-selective herbicides used in chemical weed control and atransition to herbicides which have less risk of endangering the eluvium would be made.Later weed control would be possible, however, with narrow limits because competitionlosses appear and the spreading technology is at its limits. It is still to be established in whatway reduced soil management procedures, in combination with the cultivation of herbicideresistant varieties, can be realized more certainly and without yield losses.Bt-Maize ensures an effective protection against the European corn borer which is the mostsignificant maize pest in some regions of Germany. By means of genetic engineeringprocedures a gene from the bacterium Bacillus thuringiensis (Bt) has been incorporated intothis maize. So the maize plant is able to produce a toxin which damages the European corn


borer. The questions of its selective effectiveness and the ability of the corn borer to becomeresistant have not been completely clarified (ENVIRONMENT-FEDERAL-OFFICE 1998).To guarantee fertilization in line with plant requirements would mean a great step forward.This entails that the assessment of nutrient concentrations as well as available nutrient levelsin the farm manure (semi-liquid manure) as well as in the soil could take place more quicklyand more advantageously than happens with the conventional measurement techniques.Above all, methods such that farmers themselves could apply would be advantageous.Recently considerable technical progress has been made in navigating with the help of GPS(globally positioning system) which also has an effect on agriculture. Surfaces and machinesmoving on it can be located. Broadly, a great potential to avoid environmental burdens isenvisaged through specific and exact treatment, fertilization and maintenance of land. WithGPS items can be placed with a precision of a few meters. New possibilities arise with thistechnical development, especially for proper nutrient management and chemical weedcontrol. In the cultivation of maize this technical advance could be used with positive effectsfor the environment, by distributing nutrients and herbicides on land accurately,economically, and efficiently.


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Maize is an important crop in German arable farming, with variations between regions. It

plays a dominant role in forage production. The development of the area under maize

reached a maximum in the early eighties and has remained almost constant since. Maize is

mainly used for silage, although the acreage of grain maize has increased over the last few

years, with considerable variation between years due to annual weather conditions.

Agriculture always has environmental effects. Adverse effects are in part a result of inherent

characteristics of cropping but they are strongly effected by the location of the farm (i.e.

climate and soil) as well as farm structure and farm management. The inherent effects of

maize are similar to those of other row crops, e.g. sugar beets and potatoes. Intensive maize

growing is closely related to intensive animal husbandry as maize is a highly valuable

forage. For historical reasons, intensive livestock production developed mainly in regions

which are less favourable for arable farming. This has further aggravated the environmental

problem of maize production.

Various measures to reduce the environmental impact of maize have been developed since

the eighties. New legislation came into force laying down environmental standards for

agricultural production. Additionally, agricultural research and advisory services

increasingly focus on the development of farming systems which are more friendly to the

enviroment.

Several management options for an environmentally sound maize production have already

been proved in practice: Conservation tillage systems, integrated weed management (hoeing,

band spraying, time limits), biological pest control and fertilization (mineral fertilizers,

organic manures) which take into account the nutrient demand of the crop and the supply of

the soil. However, each management strategy has to be adapted to site and farm specific

conditions.

In regions with a high density of livestock, for example in the Weser-Ems, it is important

that farmyard manure is meaningfully utilised in large quantities. Since agricultural land is,

however, normally restricted optimal fertilization management is often required. Here, maize

plays a crucial role because it does not react negatively to an excess phytilicetion like, for

example, cereals does. The export of farmyard manure into livestock-poor regions is

expensive and only practical where lawful limits (FERTILIZATION ORDINANCE) force

this.

It can be shown that in general it is possible to grow maize with less adverse environmental

effects. However, such systems are often more expensive and, hence, have not become

standard in practical farming. An improved advisory service, practical demonstration of the

possibilities and financial support have already increased the acceptance of an

environmentally sound crop management of maize. Measures to reduce adverse

environmental effects of maize in practical farming also depend on the nutrient management


of intensive livestock production systems and on the readiness of farmers to share special

technical equipment with other farmers.


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