豫南稻区土壤有效钾施肥指标研究及施钾推荐r——基于ASI法的土壤养分丰缺指标

摘要

To provide theoretic support for rice production based on formula fertilization by soil testing in the rice-growing of south Henan Province,field experiments on fertilizer efficiency of rice were carried out in rice soil district. This study used ASI(Agro Services International)method to test soil samples. According to the typical response categories(50%,50%-75%,75%-95%,95%of relative yield to soil nutrient values),we establish the abundance and deficiency indices of soil available K for rice in rice soil district based on ASI soil testing and fertilizer recommendation. The very low,low,medium,and high index for soil available K were<49.5 mg/L,49.5-85.5 mg/L, 85.5-125.5 mg/L,and>125.5 mg/L,respectively. This experiment suggested that the recommended fertilizer quantity were 150 kg/hm2,120 kg/hm2,90 kg/hm2,and 45 kg/hm2,respectively.%为给豫南区当前生产条件下水稻测土配方施肥技术的推广提供理论依据,多年来在河南南部水稻区布置水稻肥效田间试验,并用ASI法对基础土壤样品进行测试分析,以缺钾素区(NP)与推荐施肥区(NPK)水稻相对产量<50%、50%~75%、75%~95%和>95%为标准,分别将对应的土壤有效钾分成"极低"、"低"、"中"和"高"4级.研究显示运用ASI法测定的土壤有效钾含量与不施钾小区水稻相对产量呈显著正相关关系.根据水稻相对产量<50%,50%~75%,75%~95%和>95%对应的土壤有效钾指标,可以得出水稻区土壤有效钾"极低"指标为<49.5 mg/L,"低"指标为49.5~85.5 mg/L,"中"指标为85.5~125.5 mg/L,"高"指标为>125.5 mg/L.据此建立的水稻土壤养分丰缺指标推荐施钾量为:速效钾含量小于49.5 mg/L,钾肥推荐为150 kg/hm2;速效钾含量为49.5~85.5 mg/L时,钾肥推荐为120 kg/hm2;速效钾含量85.5~125.5 mg/L时,钾肥推荐为90 kg/hm2;速效钾含量大于125.5 mg/L,钾肥推荐为45 kg/hm2.