长期施肥对红壤旱地作物产量和土壤肥力的影响

历时14年的田间定位试验表明，红壤旱地磷素最为缺乏，施用磷肥对提高作物产量效果最好；施用石灰和微量元素对作物产量没有明显增产作用．施肥可以提高花生植株磷、钾的浓度，表明作物的养分含量受土壤养分供应水平的影响．土壤中赢余(亏损)的养分在养分库重建中的作用可以用速效养分库重建效率来表示．研究表明，当红壤旱地N、P2O5、K2O养分赢余1kg·hm^-2时，可分别使土壤中水解氮、有效磷、交换性钾含量提高0．6～6．26、0．20～0．28和1．1～8．5mg·kg^-1．红壤旱地氮和磷通过径流等损失较大，不同处理之间的变化幅度也较大．红壤每年可固定磷43．5kg·hm^-2，通过自身风化作用每年可提供氮48．1kg·hm^-2和钾40．5kg·hm^-2，以满足作物生长所需．

Effect of long-term fertilization on crop yield and soil fertility of upland red soil

The studies on the influence of long-term fertilization on crop yield and soil fertility of upland red soil showed that P was the most deficient in this soil, and hence, phosphorus fertilizer had the best effect on crop yield. Applying lime and microelements could not significantly increase the crop yield. The concentration of P and K in peanut could be increased if fertilizer was applied, indicating that the supply level of soil nutrients decided the nutrient concentration in plants. The reconstructive efficiency of soil available nutrient pool was dependent on the surplus or deficit of soil nutrients. When the surplus of nutrients was 1 kg x hm(-2), N was increased by 0.6-6.2 mg x kg(-1), P was increased by 0.20-0.28 mg x kg(-1), and K was increased by 1.1-8.5 mg x kg(-1). The changing in results was due to the loss of N and K from soil. The nutrient bupplying capability of soil was the quantity of the nutrients which soil could provide by weathering to satisfy the plant growth. The amount of P fixed by soil was 43.5 kg x hm(-2) x yr(-1), and that of N and K provided by soil was 40.5 and 55 x kg x hm(-2) x yr(-1), respectively.