Leaching from Maize in Denmark

High level of animal manure

Hoestaar=2009 Fsg_Navn=JyMa29 A3= Maize,220 N/ha A1= Maize, 100 N/ha C1= Maize + Ryegrass, 220 N/ha C1= Maize + ryegrass, 100 N/ha Nitrate conc. in cont. maize coarse sand, 540 mm drain, 2009

Weak Perennial Ryegrass sown 20. June, photo late autumn

To strong Red Fescue, sown with maize, photo late autumn.

Leaching [kg N/ha] in maize after G/C

When excess of nitrogen after grass/clover the leaching is increaseed considerably when applying extra nitrogen. Undersown grasses reduces the leaching considerably

Undersown grasses reduces the leaching considerably Tabel. Nitrate leaching from silage maize undersown with grasses. Preliminary results Kg NO3-N /ha Soil-typeCoarse sandFine sand Prev. crop 1) Grass/ clover MaizeGrainGrass/ clover MaizeGrain Maize ½N Maize 1N Maize 1½N Reduced leaching by undersown grasses Maize RF ½N Maize RF 1N Maize RF 1½N Maize Rye ½N Maize Rye 1N Maize Rye 1½N Average 56% reduc- tion 28% reduction

Tabel. Nitrate leaching from silage maize undersown with grasses. Preliminary results Kg NO3-N /ha Soil-typeCoarse sandFine sand Prev. crop Grass/ clover MaizeGrass/ clover MaizeGrain Reduced leaching from previus crop maize and grain compared with previus crop grass/clover, different trials. Red Maize ½N Maize 1½N Maize RF ½N Maize RF 1½N Maize Rye ½N Maize Rye 1½N Average

Typically maize silage remove more N then applied totaly Soil-typeCoarse sandFine sand Prev. crop 1) Grass/ clover Maize GrainGrass/ clover Maize N-balance [kg N/ha] Maize ½N Maize 1½N Maize RF ½N Maize RF 1½N Maize Rye ½N Maize Rye 1½N

Soil-typeCoarse sandFine sand Prev. crop Grass/ clover MaizeGrainGrass/ clover MaizeGrain Yield loss when undersown grass , [100 SFU/ha] Maize RF ½N Maize RF 1N Maize RF 1½N Maize Rye ½N50 Maize Rye 1N Maize Rye 1½N Maize grown after grass/clover is not influensed by undersown grasses. - Up to 1/3 yield loss in silage maize grown after maize or grain (low mineralizatiion), when ½ N-fertilization and undersown with a well developed red fescue

Low yield reponse in maize grown after grass/clover Soil-typeCoarse sandFine sand Prev. crop Grass/ clover MaizeGrainGrass/ clover MaizeGrain Yield responce per kg "fert-N" applied , [SFU/N] Maize 1N Maize 1½N Maize RF 1N Maize RF 1½N Maize Rye 1N Maize Rye 1½N

Conclusion Grasses undersown in maize reduces leaching. It is difficult to get the optimal balance between maize and grasses. Grasses wanted -with high N-uptake capacity -no depression on maize yield Maize after grass/clover is not affected by N or undersown grasses Maize after maize(grain) can be strong reduced be competion from undersown grasses

Extras

Soil-typeCoarse sandFine sand Prev. crop Grass/ clover MaizeGrainGrass/ clover MaizeGrain Feed "energy" yield, [100 SFU/ha], Maize ½N Maize 1N Maize 1½N Maize RF ½N Maize RF 1N Maize RF 1½N Maize Rye ½N Maize Rye 1N Maize Rye 1½N

Herbiside affects Braccica, photo 23. June

Vinterrape Foto: ISK Formyre d. 1/ Chicory Foto: ISK Formyre d 1/

Poa annua makes problems ISK, Foulumgaard d. 19/6 2009

21 Radrensning lykkedes fint, men kvik ! ISK, Foulumgaard d. 28/7-09

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