不同施氮水平和稻草添加量对水稻和玉米产量的影响

Effects of Application of N Fertilizer and Rice Straw on Grain Yields of Rice and Corn

通过盆栽试验,研究了同一土壤在淹水植稻和旱作玉米条件下,不同量氮肥和稻草配合施用增产效应,结果表明,水稻和玉米产量均随施N水平提高而显著增加,且氮肥在玉米上的产量增益作用显著大于水稻。稻草还田(土)的产量效应因氮肥水平、秸秆施加量和作物不同而异。稻草还田对水稻的增产作用明显,其中稻草施加1.5 g/kg(相当于3.6 t/hm2)与施加化肥N 0.054 g/kg(相当于130 kg/hm2)的配比能获得最佳的产量增益。稻草还土对玉米的增产效应以施稻草1.5 g/kg与化肥N 0.108 g/kg(相当于260 kg/hm2)配比最大。稻草施加量超过4.5 g/kg之后(相当于10.8 t/hm2)开始对玉米的产量形成产生负面效应,且这种负面效应随施氮水平降低而增强。从优化资源利用考虑,建议在南方双季稻区实行半量稻草原位还田,半量稻草易地还土。此外,实行稻草易地还土时要适当增加氮肥用量,避免秸秆分解过程中微生物固氮作用对旱作物生长和产量形成产生负面效应。

A result of a potted plant experiment, which was about the different yield increase effects of the application of N with incorporation office straw on rice which was under the condition of basin irrigation and corn which was under the condition of dry farming, indicates that the application of N could increase rice and corn yield obviously, and the effect on rice was more significant rather than on com. Yield effect of rice straw return depended on N fertilizer quantity, straw quantity and sorts of crop. Yield increase effect of rice straw return on rice was obvious. It got the best significant yield effect on rice that 1.5 g/kg （equal to 3.6 t/hm^2） office straws and 0.054 g/kg （equal to 130 kg/hm^2） of N fertilizers applied to rice. While 1.5 g/kg of rice straws return and 0.108 g/kg （equal to 260 kg/hm^2） of N fertilizers application could gain the best yield increase effect. It began to have side-effects on corn when the quantity reach to g/kg （equal to 10.8 t/hm^2） or more, but this side-effects began to be alleviated by the application of N fertilizer at the same time. To make the most efficient use of rice straw resources, it is recommended that half rice straw should return to the original paddy field, and the rest residue should remove to dry land. What＇s more, N fertilizer should be applied more when incorporating rice straw than no rice straw return, in order that dry farming crop＇s up-growth and yield could avoid the side-effects by microorganisms＇ nitrogen fixation during the process of the microorganisms decomposing rice straw.