非表层剖面层次土壤生产力评价研究

Evaluation of productivity of some sub-surface layers of soil profile

研究了盆栽条件下4个非表层土壤剖面层次(AB,Ab,Bk,Bg)土壤在3种肥料处理下对“京绿2号”小白菜根系发育和养分水分吸收的影响,并评价了其生长障碍因子。结果表明,各处理出苗无明显差异;施加尿素和磷二铵有利于干物质积累量增加,且磷二铵的效应更显著;施磷二铵处理的根冠比明显低于不施肥处理和施尿素处理;施加尿素和磷二铵后作物含N量增加;施加磷二铵后各土壤剖面层次土壤中的植株P浓度明显提高。综合分析表明,正常情况下只要补充N肥和P肥,作物耕层以下的各土壤剖面层次对作物生长并无明显的阻碍作用,且通过适当的耕作和灌溉,可使非耕层土壤生产力状况得到改善。

The influence of four non-surface soil profile layers （AB, Ab, Bk, Bg）on the growth of crop root system and nutrient adsorption were studied by using Chinese cabbage （Jinglu 2）cultivated in pots with 3 different fertilizer treatments： no fertilization, urea treatment, and diammonium orthophosphate treatment. The results indicate that no apparent difference among the treatments in seedling emergence is observed. The dry matter accumulation is increased with the addition of urea and diammonium orthophosphate, but the latter is much more effective. Root-shoot ratio is the lowest in the diammonium orthophosphate treatment; the plant nitrogen content is increased with the addition of urea or diammoni- um orthophosphate. Plant phosphorus content is increased apparently in diammonium orthophosphate treatment. The experimental results suggest that sub-surface soil layers show no impedient effect on crop growth, and the supplement of nitrogen and phosphorus as well as proper tillage and irrigation would help to improve the productivity of sub-surface soil.