南方红壤区稻田土壤养分动态变化及与产量关系分析

摘要

针对南方红壤区施氮量高、肥料利用率低等问题，设置了不施氮（N0）、传统施氮（CFN）2个对照处理和6个氮肥减施处理，分析了土壤养分在水稻不同生长阶段的动态变化以及与产量的关系。结果表明：在低于传统施 N 20％，等 P、K 的条件下，30％传统氮肥用量＋50％厩肥有机氮肥用量（30F ＋50M）、30％传统施氮肥用量＋50％缓释氮肥用量（30F ＋50S）产量与 CFN 持平，比80％传统氮肥用量（80F）分别增产4．7％，5．2％；其余减施氮肥处理与80F产量基本持平。30F ＋50M 处理在分蘖盛期、抽穗期、成熟期土壤有机质和有效磷含量均达到最高，碱解氮在分蘖盛期和成熟期达到最高，30F ＋50S 处理在水稻抽穗期土壤碱解氮含量最高，N0处理土壤速效钾在分蘖盛期、抽穗期、成熟期均达到最高。与产量关系分析表明，在土壤全氮、碱解氮、有效磷含量与水稻籽粒产量显著正相关，土壤速效钾含量则与产量显著负相关，其中有机质、有效磷、速效钾在不同生育时期之间存在显著正相关。因此，在南方红壤区，减施氮肥的条件下，可通过化肥配施厩肥或者化肥配施缓释肥来提高不同生育时期土壤速效养分含量来实现增产或达到传统施肥产量水平。%　　According to the high level of nitrogen application and the low Nitrogen fertilizer utilization rate , eight different treatments with different fertilizer application ,no nitrogen fertilization(N0 ),conventional fertilization nitrogen(CFN),80% chemical fertilizers and 20% farmyard manure(80F +20M),80% chemical fertilizers,30%chemical fertilizers and 50% farmyard manure(30F +50M),30% chemical fertilizers and 50% controlled-release nitrogen(30F +50S),30% chemical fertilizers and 50% green manure nitrogen in early rice and 80% chemical fertilizers and fresh rice straw in later rice ,and 80% controlled-release nitrogen with their replications were exam -ined.Each P and K application rate was the same in all the treatments .Analysis of the dynamics of soil nutrient and the relationship between the crop yields in different growth stages .The results showed that:Under the 30F +50M treatment and 30F +50S treatment,the grain yield higher the 80F 4.7% and 5.2% respectively,equal to CFN treatment.The rest of the treatment of nitrogen reduction was similar to 80F of yield.Under the 30F +50M treat-ment,the soil organic mater content and available P reached the maximum in the whole grows period and the availa -ble N reached the maximum at the active tillering stage and the mature stage .Under the 30F +50S treatment,the a-vailable N reached the maximum at the heading stage .Under the N0 treatment,the soil available K reached maximum in the whole grows period.The soil total nitrogen,available N content,available P content and rice grain yield signif -icant positive correlation,and the soil available K content is a significant negative correlation with yield .The soil or-ganic matter content,available P content and available K content in different growth periods are significantly positive correlation respectively.Therefore,chemical fertilizers and farmyard manure or chemical fertilizers and controlled -re-lease nitrogen could improve soil available nutrient content at different growth periods and increase yield or reached traditional fertilization level.