关键词: 种植业生态系统, 种植业生态系统, 能值分析, 河北

Abstract:

There are significant differences in the commercial and production of the seedlings of broccoli with different ages. The seedlings of Lvxiong 90 with age from 35 to 40 days are appropriate, which are sowed in the best time (after Aug.20) and nursery bed soil conditions, so that the ball took a good commercial and higher output.Planting density test of broccoli shows that if the domestic-based or quick-frozen are the main goal, the yield and the cost of broccoli should be taken into account and the planting density from 2200?667m-2 to 2450 strains?667m-2 is appropriate. If the fresh export is the main goal, the per unit area qualified curd output should be taken in account and the planting density in 2200?667m-2 ～2800?667m-2 is appropriate.The effects of the amount of nitrogen on the yield and the quantity of broccoli are tested and the results show that to a certain extent, the appropriate fertilizer can increase the growth and yield of the plant and curd, improve the quality of the appearance and the commercial of broccoli. But the over or less application of the nitrogen can inhibit the growth of the plant and curd on the contrary, and decrease the quality and yield eventually. In general, the amount of nitrogen (equivalent pure nitrogen) is appropriate from 25kg?667m-2 to 40kg?667m-2 under general soil fertility conditions. For the farmers, as opposed to the habit of fertilizer (about 25kg?667m-2), may be appropriate to increase the amount of nitrogen fertilizer.