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机构地区:[1]中国科学院南京土壤研究所
出 处:《生态学报》1989年第3期245-252,共8页Acta Ecologica Sinica
摘 要:本文在太湖流域研究了平原地区三个不同试验点上小麦-水稻和元麦-水稻-水稻两种轮作方式下常规稻田生态系统中氮、磷、钾、钙、镁等五种大量营养元素的循环及表观平衡状况。所考虑的输入途径有施肥、灌溉、降雨、播种及移栽;输出途径有作物收获、田面排水和渗漏淋溶。此外,氮素的输出还包括了氨挥发及硝化与反硝化脱氮。三试验点两种熟制的稻田生态系统中各元素的表观平衡状况基本一致,在土壤养分库中磷、氮有盈余,钾、镁和钙有亏损。The cycles and apparent balances (ABs) of N, P, K, Ca and Mg were studied in two kinds of normal paddy field ecosystems with the crop rotations in both the wheat-rice sequence and the barleyrice-rice sequence. The research was based upon field experiments on three critical types of paddy soils in the Tai Lake region, The transportation of concern was inputs through fertilization, irrigation, precipitation, sowing and transplantation, and outputs by crop removal, surface drainage and leaching. Nitrogen output by volatilization of ammonia, nitrification and denitrification was taken into account in addition to the outputs above. The ABs of N, P, K, Ca and Mg in two crops Systems on the soils during the period of experiment were+ 60-+ 120, +7.5-+60, -80--130, -85-+8 and -24--35 kg · ha-1 (aselement),respectively. Their input/output ratioes (I/O ratioes) in the same sequence were. 1.2-1.4, 1.2-2.2, 0.32-0.53, 0.78-1.0, and 0.70-0.85. The ABs and I/O ratioes of the same nutrient in three crops systems were +120-+ 200, +15-+ 60, -20--90. -90--130, -45--65 kg. ha-1 and 1.3-1.5, 1.5-2.2,0.53-0.82, 0.75-0.86,0.60-0.81, respectively. The ABs of a given nutrient in two types of Systems at all sites were similar:the balances of P and N were positive,while those of K, Mg and Ca were negative.
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