Analysis of Nitrogen,Phosphorus and Potassium Flows Based on Cyclic Model-A Case of Liangzhou Demonstration Area in Hexi Corridor

Considering the green agricultural model of wheat-mushroom-fertilizer-grape circular farming system in irrigated Hexi Corridor Oasis as the research object,the study about macronutrients(N,P,K) input-output ratio in different farming including field monoculture,facilities monoculture and the circular farming system were carried out to prove the material recycling pattern in the model,using a combination of quantitative research and qualitative analysis method.The results showed that the input-output ratios of N,P and K were 0.95,1.12 and 0.75 respectively in the circular farming system,which were much higher than the values in both field monoculture and facilities monoculture.The input-output ratios of macronutrients in facilities monoculture were also higher than that in field monoculture.The percentages of N,P and K between the returning field amount and the total input amount were 27%,60% and 39% respectively.So the green agricultural model of wheat-mushroom-fertilizer-grape circular farming system has rational nutrient cycle structure and it is an effective way of the fully rational and efficient utilization of local water resources and agricultural waste resources in liangzhou demonstration area.