菜园土壤速效钾丰缺指标及合理施钾量研究

Research on Abundant and Scarce Indices of Available K in Brassica parachinensis Soils and Reasonable Amount of K Fertilizer

在广东赤红壤地区含钾量不同的菜园土上选择了20个试验点进行菜心钾肥田间试验,根据试验结果建立菜心相对产量与土壤速效钾含量的回归方程.结果表明:菜心相对产量与土壤速效钾含量呈抛物线相关.施钾肥后增产的菜田占90%,增产率为0.89%～47.2%;土壤速效钾(K)的适宜含量为144.5～225.4 mg/kg;菜心产量与施钾肥量呈抛物线相关,在低、中、高肥力的菜田上种植菜心,要求菜心达到6 501～6 626、6 755～6 985、6 869～6 993kg/hm2的最高产量水平,推荐的钾肥(K2O)用量分别为67.5～78.6、67.5～75.9、67.5～70.5 kg/hm2.

Field trials were carried out to study the effects of K fertilizer on Brassica parachinensis Bailey in the soils with different indigenous K contents in Guangdong latosolic red soil areas. According to the experimental results from 20 trial sites, a regression equation between relative yield of B. parachinensis and soil available K content was established. The results indicated that their relationship was a parabola. The relative yield of 90% of the fields applied with K fertilizer increased and the growth rate reached 0. 89% -47.2%. The suitable contents of available K in soil were 144.5 -225.4 mg/kg, under which, K fertilizer should be added, but should be controlled if over it. The trial of different amounts of K fertilizer indicated that the relationship between the yield and the amount of K fertilizer was a parabola. According to the results, in order to gain 6 501 -6 626, 6 755 -6 985, 6 869 -6 993 kg/hm2 of yield, 67.5 -78.6, 67.5 -75.9, 67.5 -70.5 kg/hm2 of K fertilizer（K2O） are highly suggested to the fields with low, medium and high fertility, respectively.