一次性施肥对稻田蟹及水稻产量的影响

Effect of Single Basal Application of Fertilizers on the Yield of Rice and Crab in Rice-Crab Symbiosis System

在稻蟹种养模式下,采用田间微区法系统地研究了一次性施肥技术条件下,不同有机无机氮肥配比对耕层土壤和田面水中的NH4＋和NO3-含量变化以及对河蟹和水稻产量、效益的影响。结果表明：施肥能明显增加水稻土壤、水面中的NH4＋和NO3-含量,施肥后3~7 d左右达到最高值,随后迅速下降并趋于稳定。水田氮素形态以NH4＋为主、NO3-次之;与常规施肥（FP）和测土推荐施肥（OPT）相比,A1配方肥一次性施用对河蟹的生长及产量均有较好的效果,同时水稻产量也较高,达到10620.5 kg hm-2,接近于OPT处理;河蟹成活率达66.7%,明显好于其他处理;亩效益分别比FP和OPT处理增加了165.4元和120.7元。而OPT处理只在水稻产量反应较好,对河蟹生长有一定的影响。说明,合理的有机无机肥配比能够实现稻蟹双丰收的目标。

The effects of different ratios of organic and inorganic nitrogen fertilizers on the NH4＋ and NO3-contents in soil and water and the yield of rice and crab,as well as the economic benefit were investigated using single basal application of fertilization technique in rice-crab symbiosis system.The results showed that application of N fertilizer could significantly increase NH4＋ and NO3-contents in soil and water.NH4＋ and NO3-contents had reached the highest level from the third day to the seventh day after fertilization,and then decreased sharply to a stable level.As far as the forming of nitrogen element was concerned,NH4＋ occupied the first position followed by NO3-.Comparing to conventional famer practice（FP） and optimum fertilization（OPT）,treatment A1（balanced fertilization） exerted an effective influence on the growth and yield of crab,and the rice yield reached 10620.5 kg hm-2 which closed to treatment OPT.Also,the survival rate of crabs was as high as 66.7%,which was evidently higher than the other treatments.The economic benefit analysis showed that the incomes of treatment A1 were separately 165.4 Yuan/ha2 and 120.7 Yuan hm-2 higher than FP and OPT treatment.As for OPT treatment,it seemed more suitable for rice instead of crabs.This experiment indicated that a rational application of organic and inorganic nitrogen fertilizer could be beneficial to both rice and crab in rice-crab symbiosis system.