摘要
通过对 7种不同时空类型的华北棉区棉田生态系统能流、价值流和 N、P、K变化的研究表明 ,华北棉区棉田生态系统的能量生产为 3 0 .41× 1 0 3～ 71 .63× 1 0 3k J/(m2· a) ,纯收入为每 hm2 3 5 65 .80～ 81 46.5 0元 ,主要能量投入为劳动力的投入 ,占总投入能的 75 .80 %～ 81 .1 4%。其在不同时空类型棉田所表现出的变化特征为 :随着播种期的推后 ,棉田内害虫的取食为害作用增加 ,天敌的捕食作用减少 ,光能的利用效率下降 ,棉田经济效益降低 ;实行间套作 ,棉田内害虫的为害作用和天敌的捕食作用均增加 ,光能利用率增加 ,棉田经济效益上升 ;进行免耕种植 ,棉田内害虫的为害取食作用减少 ,天敌的捕食作用增加 ,光能利用率增加 ,棉田经济效益上升。由此进一步探讨了华北棉田生态系统生态调控的途径。
The energy flow 、value flow and soil N、P、K dynamics have been evaluated and compared by collecting the agronomic data and determining the energy parameters of crop, pest and natural enemies in 7 types of cotton agroecosystems from Northern China. The results showed that the output of energy and pure monetary values in 7 types of cotton agroecosystems were 30 41×10 3～71 63×10\+3kJ/(m\+2·a) and 3565 80～8146 50 Yuan RMB/(hm 2·a), respectively. The output input ratio of energy and monetary values were 1∶0.746～2 103 and 1∶1 34～2 494, respectively. The major input of energy was for manpower, which accounted for 75 80%～81 14% of total energy input. The higher utilization efficiency of solar energy and economic efficiency were found in intercrop cotton agroecosystems and no till cotton ecosystem; However,the lower utilization efficiency of solar energy and economic efficiency took place in cotton agroecosystems when cotton planting time was delayed. The damage of pests to crops increased in intercrop cotton and planting time delayed cotton agrocosystem and decreased in no till cotton agroecossytem. The predation of predacious enemies to pests was increased in intercrop cotton agroecosystems and no till cotton ecosystems and decreased in cotton planting time delayed cotton agroecosystem . The ways to regulate and manage cotton agroecosystems were also discussed in this paper.
出处
《生态学报》
CAS
CSCD
北大核心
2002年第9期1433-1439,共7页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目 (3 9970 1 3 7)
国家重点基础研究 (973 )资助项目 (G2 0 0 0 0 1 62 0 9)
中国科学院创新工程方向资助项目 (KSXC2 -0 1 -2 )
