Studies On Fertilizer-required Characteristics Of Potato And Precise Fertilization Technique By Dry Farming

As the traditional advantage of grain and food crops in combination, Potato has became the first major crops in Ningxia, but the shortages aspects of yield and quality increasingly highlighted, behind the increase of planting area year by year. Consequently, Based on several field experiments and test analysis, the Soil nutrient condition were understood, the absorption and transfer of NPK of potato were explored, the rule of potato yield and quality under different fertilizer were determined in this paper, and finally put forward the fertilizing methods concerning the reasonable quantity of NPK under the condition of drop-irrigation in dry land. The main results were as follows:(1) The soil efficiency status of main potato planting fields in arid and semi-arid area of Ningxia is lack of organic matter, low nitrogen, suitable of phosphorus, abundant of potassium. The ragional different of nutrients is:Southern Mountain>Middle Arid Zone.(2) The tuber yield,quality and the amount of nutrients content in different organs of potato apparently raised as the increasing of fertilizer within a certain range, but it would be slow down or even decline when beyond the limit. Under the conditions of the tested soil,0.59kg nitrogen,0.28kgP2O5and1.15kg K2O were needed to form100kg grain.(3) The amount of nutrients content, cumulate and allocation proportion in each organs of potato presented dynamic changes.In the early of growth stages, the nutrients supplied for the overground part, the regularities of distribution of NP was:leaf> Stem>tuber, K was:Stem>leaf> tuber. After that nutrients transferred to the underground part,the tuber finally became the storage vault. The order of the accumulation in different period was bulking stage> starch accumulation stage>seeding stage>maturation stage. The absorbed dose of nutrient elements was:N>K>P.(4) Make up with the fertilizer effect equation according to the experiments, it showed that under the foundation of farmyard manure2.5t/666.7m2, ameliorant I200kg/666.7m2, when N12.84kg/666.7m2,P2O56.74kg/666.7m2,the potato reached largest yield, it is1430.9kg/666.7m2and1446.4kg/666.7m2. The optimum economic fertilizing is:N12.52kg/666.7m2,P2O56.56kg/666.7m2, the yield is1430.6kg/666.7m2and1446.1kg/666.7m2.(5) On the basis of production practice, most of the farmers overdose applied nitrogen, use less PK and barely applied organic manure, the rational fertilization of oil sunflower (the target production was1200～1400kg/666.7m2) was:N4.12-9.68kg/666.7m2,P2O50.56-4.066kg/666.7m2, convert into urea9.0-21,0kg/666.7m2, triple superphosphate1.3-9.2kg/666.7m2. Phosphorus, potassium, ameliorant and the farmyard manure were one-off as the base fertilizer,70%Nitrogen should be fertilized in the beginning and30%in the squaring period.