不同施肥模式对下辽河平原水稻生态系统生产力及养分收支的影响

采用田间肥料试验,研究了不同施肥模式对稻田生态系统的生产力和养分收支的影响。结果表明:随养分配施均衡程度的增加,系统的生产力逐渐提高,其中氮磷钾处理的生产力最高;氮肥对水稻生产力的贡献最大(对生物量的贡献约20%,对籽实产量的贡献约34%),磷肥和钾肥的贡献相当;在水稻各部位对氮、磷、钾养分的吸收中,氮的吸收主要集中在籽实和秸秆中,磷的吸收则主要集中在籽实中,钾的吸收主要集中在秸秆中;在各施肥处理中,土壤全量养分和有机质的变化不大,而速效养分的变化较大,特别是速效磷库和速效氮库;单施化肥处理的土壤,其速效养分含量不高,而施有机肥处理土壤的速效养分含量较高,表明有机肥较有利于土壤养分的积累。

Productivity and nutrient budget of rice ecosystem in lower reaches of Liaohe River plain under effects of different fertilization patterns

To study the effects of different fertilization patterns on the rice ecosystem's productivity and nutrient budget in the lower reaches of Liaohe River plain,a field experiment was conducted at the Shenyang Ecological Experimental Station of Chinese Academy of Sciences The results showed that with the increasing degree of balanced fertilization,rice ecosystem's productivity increased gradually,being the highest in treatment NPK.Among the chemical fertilizers,N fertilizer contributed most to the rice productivity(20% to biomass and 34% to grain yield),while P and K fertilizers had the similar contribution rates.As for the allocation of the absorbed nutrients in rice plant,N was mainly in grain and stalk,while P and K were more concentrated in grain and in stalk,respectively.Under fertilization,less fluctuation was observed on the contents of soil organic matter and total N,P and K,but the amounts of soil available nutrients varied greatly,especially for available P and available N.Fertilization with organic manure induced a higher content of soil available nutrients,compared with applying chemical fertilizers alone.