莴笋-空心菜-莴笋种植模式下不同改良剂对退化土壤中植株养分利用的影响

Effects of fertilizer and soil additives on plant nutrient utilization in a degraded soil

在退化土壤中添加不同改良剂,通过莴笋-空心菜-莴笋的盆栽试验,对比分析了6种改良剂对蔬菜产量、品质、养分的影响,以期为评价改良剂对退化土壤中的植株养分的利用效果提供科学依据。结果表明,1）不同改良剂处理能有效提高蔬菜产量,其中化肥配施生物质灰渣（NPKH）和化肥配施生物肥（NPKW）处理的蔬菜产量增幅最大。2）各处理较CK提高了蔬菜体内NO3--N含量,本试验中莴笋的硝酸盐含量符合GB/T15401规定,未对莴笋品质产生不利影响;而化肥配施改良剂比单施化肥（NPK）有利于降低莴笋中NO3--N含量,以NPKW处理最佳,较NPK处理下降了7.8%~63.0%。与单施化肥相比,NPKH处理提高了蔬菜氨基酸含量,降低了硝酸盐含量,提高了氮肥表观利用率。3）NPKH处理的肥料农学利用率较高,可以有效提高莴笋中全磷、全钾含量,其中全钾含量较CK显著提高了43.4%~58.9%;NPKH和NPKW处理在空心菜种植期间,对氮肥、磷肥、钾肥的农学利用率较高,提高了空心菜对全氮、全磷、全钾营养元素的吸收量。研究表明化肥配施改良剂,特别是化肥配施生物质灰渣或生物肥可以提高蔬菜养分利用率,增加产量的同时降低硝酸盐的累积。

The objective for this study was to provide a scientific basis for evaluating the effects of different amelioration methods on plant nutrient utilization in degraded soil by analyzing their influence on yield,quality and nutrient content of vegetables.Seven amelioration treatments were assessed across four different vegetables including lettuce and water spinach.Compared with the control（CK）,amelioration treatments improved the yield of vegetables,especially NPKH（N-P-K fertilizer＋biomass ash）and NPKW（N-P-K fertilizer＋biological fertilizer）.Amelioration treatments increased the nitrate（NO3--N）content of vegetables compared with CK.The nitrate content of lettuce complied with Regulation GB/T15401,suggesting it did not reduce the quality of lettuce.Nitrate contents under the fertilizer plus amendment treatments were lower than those under the fertilizer（NPK）only treatments;nitrate content for the NPKW treatment was 7.8%-63.0%lower than NPK treatments.The NPKH treatment increased amino acid content,reduced nitrate content and improved apparent N recovery rate of N fertilizer.NPKH also markedly improved P and K contents in lettuce.However,compared with the CK,the K content of lettuce under NPKH was reduced by 43.4%-58.9%.The fertilizer utilization efficiency under NPKH and NPKW was higher than other treatments in water spinach,increasing the N,P,K content of water spinach under these treatments.This research indicates that fertilizer application with amendments can maintain high vegetable crop yields and stimulate N uptake and transformation by the crop.