秸秆钾替代化肥钾对莴笋的营养效应研究

在重庆地区多年种植蔬菜的两个基地进行田间试验,研究了秸秆钾替代化肥钾对莴笋的产量、品质、养分吸收量和钾素利用率的影响。秸秆钾替代化肥钾较无钾肥处理极显著提高两个试验点莴笋产量,增产11.4%~13.7%和11.4%~15.3%,各处理产量大小为:MH+KL(有机肥钾50%+化肥钾50%)MM+KM(有机肥钾30%+化肥钾70%)ML+KH(有机肥钾10%+化肥钾90%)CK2(常规施钾处理)CK1(无钾肥处理),以高量(50%)秸秆钾处理(MH+KL)增产作用最大。秸秆钾替代化肥钾较常规施钾提高莴笋产量,但增产作用不显著。两个试验点秸秆钾替代化肥钾显著降低莴笋叶维生素C和可溶性糖含量,降幅分别为4.7%~16.8%和3.2%~30.5%,但对莴笋茎该两个品质指标略有提高;莴笋叶硝酸盐含量增加8.0%~8.2%和11.4%~17.2%,莴笋茎硝酸盐含量在试验点1降低2.5%~11.5%,而试验点2则增加8.0%~13.5%。试验点1莴笋叶钙、镁、铁和锰含量为提高,试验点2降低。两个试验点秸秆钾替代化肥钾均显著提高莴笋对氮、磷和钾吸收量,以MH+KL处理莴笋钾素利用率最高。综合莴笋产量、品质、养分吸收和钾素利用效率,以MH+KL处理效果最佳。

Effects of Straw Potassium Replacing Chemical Potash Fertilizer in Lettuce Production

Field experiments were carried out in two vegetables planting bases of Chongqing to study the effects of straw potassium replacing chemical fertilizer potassium on the yield, quality, nutrient uptake and potassium utilization rate of lettuce. 5 treatments were designed, including CK1 (no chemical K), CK2 (ordinary chemical K), ML+KH (10% maize straw K + 90% chemical K), MM+KM (30% maize straw K + 70% chemical K ), MH+KL (50% maize straw K + 50% chemical K ). The results showed that lettuce yields were significantly increased in the two bases (by 11.4%–13.7% and 11.4%–15.3%, respectively) with an order of MH+KL>MM+KM>ML+KH>CK2>CK1. Compared with CK2, the treatments with maize straw K replacing chemical K was not significant in increasing lettuce yield, while reduced significantly Vc and sugar contents in lettuce leaves (by 4.7%– 16.8% and 3.2%–30.5%, respectively), while slightly increased the two indexes in lettuce stem. Nitrate contents were increased significantly in lettuce leaves (by 8.0%–8.2% and 11.4%–17.2%, respectively), while nitrate content in lettuce stems decreased by 2.5%–11.5% in basis 1 but increased by 8.0%–13.5% in Basis 2. The contents of calcium, magnesium, iron and manganese in lettuce leaves were increased in Basis 1, but calcium content was decreased in Basis 2. Straw K replacing chemical fertilizer K increased significantly the uptake of lettuce to nitrogen, phosphorus and potassium, and MH+KLtreatment had the maximum K utilization efficiency, which is the optimal for lettuce production if taking yield, quality and nutrient uptake into consideration.