仙桃市中稻土壤丰缺指标体系的建立及推荐用量研究

[目的]通过开展中稻“3414”试验,合理确定土壤养分等级和施肥量,为指导仙桃市中稻科学施肥提供依据.[方法]在不同土壤肥力的中稻田块进行多点中稻“3414”田间试验,分析不同土壤肥力水平下中稻土壤有效养分含量与相对产量的相关性,建立中稻土壤养分丰缺指标和不同土壤肥力的施肥指标.[结果]仙桃地区中稻土壤氮磷钾均处于缺乏状态.适当施用氮磷钾肥可显著提高中稻产量.[结论]根据中稻土壤碱解氮、有效磷及速效钾含量,可将碱解氮划分为低（30～60 mg/kg）、中（60 ～ 120 mg/kg）和高（＞120 mg/kg）3级；将有效磷含量划分为低（3.5 ～7.5 mg/kg）、中（7.5～15 mg/kg）和高（＞15 mg/kg）3级；将速效钾含量划分为低（25 ～ 55 mg/kg）、中（55 ～ 110 mg/kg）和高（＞110 mg/kg）3级.当土壤碱解氮含量处于低、中和高等级时,氮肥推荐用量分别为210 ～ 225、195 ～210和180～ 195 kg/hm2;当土壤有效磷含量处于低、中、高等级时,磷肥推荐用量分别为75 ～90、60 ～75和小于60 kg/hm2；当土壤速效钾含量处于低、中和高时,钾肥推荐用量为82.5 ～ 97.5、67.5 ～82.5和小于67.5 kg/hm2.

Establishment of Soil Nutrient Abundant Deficiency Index in Middle-Season Rice Field, Xiantao City and Study of Recommended Fertilization Amount

[Objective] By conducting middle-season rice ＂3414＂ experiment, reasonable soil nutrients and fertilizer grade were determined to provide the basis for guiding scientific fertilization of middle-season rice. [ Methods ] In different soil fertility of middle-season rice field, ＂3414＂ field experinmnt was can＇ied out. The correlation of soil available nutrients content and relative yield under different soil fertility level was analyzed. Soil nutrient abundant deficiency index and different fertilization index of soil fertility were studied. [ Result ] In Xiantao middle- season rice soil, N, P, K were lack of status. The appropriate use of N, P and K fertilizer could significantly increase rice production. [ Con- clusion] According to the rice soil alkali-hydrolysable nitrogen, available phosphorus and available potassium content, alkaline hydrolysis ni- trogen could be divided into low （30 -60 mg/kg）, medium （60 - 120 mg/kg）, high （ 〉 120 mg/kg） level, available phosphorus content was divided into low （3.5 -7.5 mg/kg）, medicm（7.5 - 15 mg/kg） and high （ 〉 15 mg/kg） level, and available potassium content was di- vided into low （25 -55 mg/kg）, medium （55 -110 mg/kg） and high （ 〉 110 mg/kg） level. When soil alkali-hydrolysable nitrogen content in low, medium and high grade, the dosage of nitrogen fertilizer recommendation were 210 - 225, 195 ＂- 210 and 180 - 195 kg/hm2 respective- ly. When soil available phosphorus content in low, medium and high grade, the dosage of phosphate fertilizer recommendation were 75 - 90, 60 - 75 and less than 60 kg/hm2 respectively. When soil available potassium content was low, medium and high, potash fertilizer recommen- ded dosage were 82.5 - 97.5, 67.5 - 82.5 and less than 67.5 kg/hrn2 respectiuely.