不同耕作与施肥方式下白土水稻产量及养分吸收量

通过定位试验，研究白土上不同耕作措施及有机肥施用对水稻产量、 养分吸收量及土壤理化性状的影响。试验设置2个翻耕深度（10 cm和20 cm）与4种施肥模式（单施化肥、 化肥+畜禽粪、 化肥+秸秆、 化肥+绿肥）。结果表明，单施化肥时，翻耕20 cm处理两年的平均产量较翻耕10 cm处理减产7.6%; 而在翻耕20 cm的基础上，秸秆还田或施用畜禽粪、 绿肥则可以显著提高水稻产量，较单施化肥分别增产14.8%、 16.1% 和14.6%。水稻养分吸收量也表现出相同规律，在翻耕20 cm后补充有机肥能显著增加植株对氮、 磷、 钾的吸收。同时，翻耕 20 cm结合秸秆还田或施用畜禽粪、 绿肥处理的土壤有机质、 全氮、 碱解氮、 速效磷和速效钾含量均高于单施化肥处理。在白土稻田上，翻耕20 cm后增施有机肥有利于提高水稻产量，促进养分吸收，改善白土耕层土壤理化性状，是适合白土区大力推广的施肥模式。

Rice yields and nutrient uptake under different ploughing depthsand fertilizations in white soil

Field experiments were conducted to study effects of different phonghing depths  and fertilizations on rice yields,  nutrient uptakes  and soil physical and chemical properties in white soil of paddy fields. The treatments consisted of two ploughing depths of 10 cm and 20 cm (T₁₀, T₂₀) and four fertilization systems of chemical fertilizer (F),   chemical fertilizer and farmyard manure (F+M),   chemical fertilizer and wheat straw (F+S),   chemical fertilizer and green manure (F+G). The results show that compared to the T₁₀+F,  rice yield is decreased by 7.6% in the T₂₀+F,  and the applications of wheat straw,  farmyard manure,  and green manure with ploughing depth of 20 cm can significantly increase the yields by 14.8% (T₂₀+F+S),  16.1% (T₂₀+F+M) and 14.6% (T₂₀+F+G),  respectively. Similar patterns are showed in N,  P and K uptakes. The contents of soil organic matter,  total N,  available N,  available P and available K in the T₂₀+F+S,  T₂₀+F+M,  and T₂₀+F+G treatments are higher than those in the T₁₀+F and T₂₀+F treatments. In conclusion,  the application of organic manure combined with ploughing depth of 20 cm in white soil can increase rice yields and nutrient uptakes,  improve soil fertility in plough layer,  and can be recommended for rice production in white soil areas.