Preliminary Establishing The System Of Abundant And Deficient Index Of Soil Nutrient And Fertilization For Alfalfa Production In The Bashang Area

The alfalfa (Medicago sativa L.)is the high-quality perennial legume family herb, having a growing demand potential. In order to better increasing production, improving quality, it is imperative to carry out fertilization of alfalfa. Through the field fertilization experiment with fertilizer response function method,the experiments is taking to determine the optimal fertilization of N/P/K and the highest yield of alfalfa in the Bashang areas of Hebei Province. At the same time, the experiments determine the best fertilizer combination of Fe/Mn/Cu and Zn micro-fertilizer. Through the pot fertilization experiment with the method of nutrient abundance and deficiency index, the experiments is taking to determine the abundance and deficiency index of available phosphorus, available potassium, available iron, available manganese, and available zinc for alfalfa soil in the Bashang area. Main results obtained were as follows:1 The findings of study on fertilization of alfalfa production in the Bashang areaThe N-P-K experiments took at the block in the Bashang area. Through the unary quadratic equation of fertilizer effect, the experiments show that the content of nitrogen is in middle degree, the content of potassium is abundant, and the content of phosphorus is deficient. Alfalfa fertilization treatments can increase output by 26%～68% except treatment No.4 yields less than the comparison, yield-increasing effect is significant. As the effect of fertilizer application, its shows that phosphorus is the best, nitrogen is good, potassium is worst. Treatment No.7 can increase yield by 68%, that is to say fertilizes N 100 kg/hm2, P2O5 300 kg/hm2, K2O 100 kg/hm2. Through the ternary quadratic equation of fertilizer effect, the experiments show that when fertilize N 82.6 kg/hm2, P2O5 216.8 kg/hm2, K2O 48.2 kg/hm2, the highest-yield is 4326.6 kg/hm2.The Fe-Mn-Cu-Zn experiments took at the block in Bashang area. Through the variance analysis and F-test, the experiments show that the impact of manganese, zinc on alfalfa yield reached a significant level. The impact of copper, iron on alfalfa yield reached a insignificant level. The best fertilization combination is F3M2C3Z2, that is to say fertilize Fe 20 kg/hm2, Mn 3 kg/hm2, Cu1.8 kg/hm2, Zn 2 kg/hm2. As the effect of fertilizer application, its shows that manganese is the best, zinc is good, copper is bad, iron is worst. The recommended application amount of manganese is 3 kg/hm2, while the recommended application amount of zinc is 2 kg/hm2. The recommended application amount of copper and iron should take some further studies to determine.2 The abundance and deficiency index of soil nutrient for alfalfa in the Bashang area.This study further verified that the abundance and deficiency index of soil nutrient does not apply to nitrogen, and the experiments also identified the abundance and deficiency index of five kinds of elements. The result showed that planted alfalfa in Bashang area, its abundance and deficiency index of nutrient were as follows (five degrees):Available phosphorus:<3.5.3.5～9.8,9.8～21.4,21.4～27.7 and>27.7 mg/kg; available potassium:<2.4,2.4～15.6,15.6～63.4,63.4～101.2 and> 101.2 mg/kg; available iron<4.9,4.9～15.1,15.1-35.3.35.3～46.9 and>46.9 mg/kg; available manganese<3.3,3.3～13.1,13.1～36.9,36.9～52.0 and>52.0 mg/kg; available zinc< 0.4,0.4～1.2,1.2-2.9,2.9～3.9 and>3.9 mg/kg.