红壤稻田系统有机物循环再利用潜力及增产作用

10年田间试验结果表明：红墩妥田系统有机养分循环再利用潜力大，水稻收获，年均从稻田系统中输出NPK的总量最大可达到224.7,53.0和271.4kg/hm^2，有机物循环再利用，年均可归N，P，K量最大分别为115.1,35.8和231.5kg/hm^2，占系统输总量的51.2%,67.5%g和85.3%，保持稻田系统内有机物循环再利用可提高系统生产力，在不施化肥的情况下，增产3056kg/hm^2，增施N肥，增产2753kg/hm^2，增施N，P肥，增产1543kg/hm^2；NPK配合，增产984kg/hm^2；有机物循环再利用还可增强稻田系统的稳产性能，降低稻谷产量的年际变异系数；有机物循环再利用对水稻的增产有着明显的残效叠加作用，在施用N，P，K化肥基础上圾机物养分循环再利用水稻增产率在试验期间的前5年为7．2％，后5年平均为9．4％。

POTENTIAL AND YIELD-INCREASE EFFECT CAUSED BY ORGANIC MATTERS RECYCLING IN RED PADDY SYSTEM

The results of field experiments within 10 years in red paddy systems indicated the potential of recycling organic matters was significantly great. The amount of N, P and K outputs by rice harvest were up to 224.7, 53.0 and 271.4 kg/hm 2, respectively. The amount of returning N, P and K nutrients were up to 115.1, 35.8 and 231.5 kg/hm 2 using the method of organic matters and were 51.2%, 67.5% and 85.3% of the output of the paddy system, respectively. Under recycling nutrients, the yields of rice increased were 3 056, 2 753, 1 543 kg/hm 2, and 984 kg/hm 2 based on fertilizing nothing, N, NP and NPK respectively. It could increase the ability of stabilized yield of the system and decrease the annual variation coefficient of grain yield under organic matters recycling in red paddy systems. Variation coefficient of the cycling treatments is smaller than that of no cycling treatment. There was a marked accumulative residual effect of recycling nutrients on crop yield, based on NPK fertilizers, the average increase rate of crop yields caused by recycled nutrients was 7.2% in the first five years, but raised up to 9.4% in late five years within the experimental period.