不同耕作深度与施肥量对江汉平原稻田土壤紧实度和水稻产量的影响

Effects of different tillage depths and fertilizer rates on soil compaction and grain yield in paddy fields in Jianghan plain

连续两年(2014—2015年)在湖北省潜江市浩口镇进行大田试验,研究了3个耕作深度和4个施肥水平对稻田土壤紧实度和水稻产量的影响。结果表明,水稻栽插前深耕(30 cm)相对于浅耕(10 cm)和中耕(20 cm)对土壤的扰动较大,但经过整个水稻大田期沉降之后,对表层土壤的紧实度影响很小,能明显降低中层土壤的紧实度,能明显增加下层土壤的紧实度,形成"上松下紧"的结构,但耕作深度对水稻产量没有显著影响。在氮(N)、磷(P2O5)、钾(K2O)按1∶0.5∶0.8配比的条件下,用线性+平台模型确定的中稻氮肥最合理用量为156.5 kg/hm2。

The field experiment was conducted to study the impract of different tillage depths and fertilizer rates on soil compaction and grain yield in paddy fields in Jianghan plain in two consecutive years(2014-2015).The results indicated that the effect of deep plowing prior to planting on paddy soil were significant for the soil as compared with shallow plowing and tillage,but after settling throughout the field,the compactness of topsoil was affected weakly,the compaction degree of middle soil was obviously reduced,the compaction degree of the lower soil was obviously increased,then form the structure of“up-loose-down-tightness”,but which had no significant effect on the yield of rice.The reasonable N application rate for mid-rice was 156.5 kg/hm^2 determined by linear+platform model under the condition of 1∶0.5∶0.8 ratio of nitrogen,phosphorus(P2O5)and potassium(K2O).