水稻土磷素分配特征及施肥对其影响的研究

为了研究水稻土磷素分配特征及施肥对其的影响。调查了水田和旱田的磷素分布状况,采用最优设计法研究了施肥对水稻土磷素分布的影响。菜田土和旱田土磷素分布为:速效磷占全磷的比例为0~24 cm层大于>24 cm层,而水稻土是>24 cm层中的速效磷含量远高于0~24 cm层,速效磷占全磷的比例规律亦如此。通过数学模型分析可知施有机肥、施氮、施磷和施钾4因素中,某一因素均以其他3因素代码值为零水平时土壤0~24 cm层速效磷占全磷比值最高,在土壤>24 cm层速效磷占全磷比值最低。土壤速效磷占全磷比值在0~24 cm层≥1.8和在>24 cm层≤2.5的优化施肥措施是施牛粪22 890.6~23 772.1 kg/hm2,N 133.8~136.9 kg/hm2,P2O559.7~63.8 kg/hm2,K2O 107.4~112.6 kg/hm2。该研究为水稻合理施肥提供了依据。

Study on the Phosphorus Distribution Characteristic in Paddy Soil and the Effect of Fertilization on Phosphorus Distribution

The study aims to investigate the phosphorus distribution characteristic in paddy soil and the effect of fertilization on phosphorus distribution.The distribution status of phosphorus in paddy field and dry farm were investigated.The effect of fertilization on phosphorus distribution in paddy soil was studied with the optimum deign method.The phosphorus distribution in vegetable soil and dry soil was that the proportion of quick acting phosphorous in total phosphorous was higher in layer 0～24 cm than that in layer >24 cm.In paddy soil,the quick acting phosphorous content was much higher in layer >24 cm than that in layer 0～24 cm,the proportion law of quick acting phosphorous in total phosphorous was the same.It was learned through mathematics model analysis that in 4 factors such as applying organic fertilizer,nitrogen,phosphorous and potassium,when the code values of 3 factors were 0,the proportion of quick acting phosphorous in total phosphorous was highest in layer 0～24 cm and lowest in layer >24 cm.When the ratio of quick acting phosphorous to total phosphorous in 0～24 cm layer was greater than or equal to 1.8 and that in >24 cm layer was less than or equal to 2.5,the optimized fertilization measure was as follows:cow manure 22 890.6～23 772.1 kg/hm2,N 133.8～136.9 kg/hm2,P2O5 59.7～63.8 kg/hm2 and K2O 107.4～112.6 kg/hm2.The study supplied basis for reasonable fertilization of rice.