关键词: 人力资本, 人力资本, 经济增长, 趋势, 预测, 寿光市

Abstract: For studying on soil nutrient supply status under greenhouse and effect of N,P,K fertilization on lettuce, a balance fertilization experiment with “3414” design was carried out on a facility field in Songgezhuang village, Shunyi district of Beijing. The results showed that when N was 210 kg•hm-2, P2O5 was 90 kg•hm-2 and K2O was 150 kg•hm-2, the yield was 59967.0 kg•hm-2, and the phosphorus and potassium fertilizer had no significant influence on lettuce yields, demonstrated that the experimental soil was not lack of available phosphorus, and potassium. Regression analysis indicates that the dose of 164 kg•hm-2 N can give the best economic yield of 59115.8 kg•hm-2. The result also showed that the fertilizer recoveries by lettuce were very low, in which the highest value was potassium with only 12.0%, nitrogen was 5.9% and phosphorus was no higher than 5.1%. In the balance indexes of nutrition for N, P, K, the highest index for K was only 1.73, and the lowest one for P was 0.27. These results also indicated that the recoveries of chemical fertilizer nutrient were very low, so the soil nutrition needs to be monitored regularly, and fertilizing carefully, avoiding from resources waste.