湖北省油菜施硼效果及土壤有效硼临界值研究

Study on Response of Rapeseed to Boron Application and Critical Level of Soil Available B in Hubei Province

【目的】从区域角度研究湖北省油菜主产区硼肥施用对油菜(Brassica napus L.)生长及产量的效果,确定目前生产条件下土壤有效硼临界值,为油菜科学施肥提供依据。【方法】2005～2006年在湖北省布置30个田间试验研究油菜施硼产量效应,结合土壤有效硼含量确定缺硼临界值。【结果】施硼对油菜的营养生长及产量构成因素均有促进作用,30个试验点施硼平均增产油菜籽428kg·ha-1,平均增产率19.2%,70%的试验增产效果显著,增产量超过500kg·ha-1的试验点占26.7%;土壤有效硼含量与施硼效果呈极显著负相关;按照不施硼产量相对于施硼处理的90%作为判断标准,土壤有效硼临界值比20年前第二次土壤普查时确立的临界值有所提高。【结论】湖北省油菜施用硼肥增产效果显著,现阶段油菜种植的土壤有效硼临界值为0.58mg·kg-1,大约80%的地块在种植油菜时需要施硼。

【Objective】 In order to provide a scientific basis for balanced fertilization, the effect of boron fertilization on growth and yield of rapeseed （Brassica napus L.） was studied and soil critical available B was determined based on field trials in main rapeseed producing region of Hubei Province. 【Method】 Thirty field trials of B fertilizer application to rapeseed were conducted in 2005-2006 growth season. The soil critical value of B deficiency was determined according to the effect of B fertilizer on seed yield and soil available B content.【Result】The results showed that B application promoted the vegetative growth and yield components of rapeseed. The average increment with B fertilization was 428 kg·ha^-1 and the increasing rate was 19.2% for all 30 trials. Compared to the control （no B treatment）, the yield of about 70% trails significantly increased by B application, and the percentage of yield increment more than 500 kg·ha^-1 was as high as 26.7% for all trials. The results indicated that the yield increment by B application had significantly negative corretation with soil available B content. Based on the relative yield of CK/＋B at 90 percent level, the soil critical available B was 0.58 mg·kg^-1 which was higher than that in the 1980s determined by the second nationwide general soil survey achievement.【Conclusion】The yield-increasing effect of B fertilizer on rapeseed is notable and the soil critical available B is 0.58 mg·kg^-1 in Hubei Province at present. According to the soil B deficiency criterion, it is necessary to apply B fertilizer for about 80% rapeseed cultivated field in Hubei Province.