Comparative Study And Evaluation Of Water And Fertilizer Management In Different Cropping Systems In Tianjin

The main way to increase crop yield is to use fertilizer,but excessive fertilization will not only reduce crop yield and quality,but also cause waste of resources and water and soil pollution.Based on the investigation of the present situation of water and fertilizer application of agriculture production in Tianjin area and the relevant literature results referred,the study carries out comprehensive evaluation for fertilization and irrigation in agricultural production of Tianjin area and puts forward suggestions.The aim is to promote the agricultural modernization production in Tianjin area to achieve efficient use of resources,to reduce agricultural non-point source pollution and provide theoretical guidance and technical support for sustainable development of local agriculture.The result shows:(1)In the input of nitrogen,phosphorus and potassium in different cropping systems in Tianjin,farmland and open vegetable field mainly use chemical fertilizer,and protected vegetables mainly apply organic fertilizer,whose main variety is chicken manure.The nitrogen input in grainfield is shortage,the nitrogen input in protected vegetable field and open vegetable field are excessive.The phosphorus input in each cropping system is in short supply.The potassium input of grainfield is deficient,and the protected vegetable fields and open vegetables field are mostly in the state of excess potassium input.(2)In the aspect of nitrogen phosphorus and potassium surplus under different cropping systems in Tianjin city,and nitrogen in greenhouse field vegetables and open vegetable fields are in surplus,and the surplus is in the sate of high risk of nitrogen environment.Grain nitrogen has a small surplus,which has the potential nitrogen environmental risk.Phosphorus of various cropping system are in surplus,so the content of available phosphorus in soil of different planting system is high,facing the phosphorus environmental risk of soil,especially in vegetable fields.(3)In the way of irrigation,grainfield mainly adopts flooding,and protected vegetable field and open vegetables field use the way of furrow irrigation.The water sources of all planting systems are mainly from underground water.The irrigation amount is too high and the water use efficiency is low.