The Effects Of Different Farming Systems On Wheat Yield, Soil Fertility Properties And Nutrients Loss

According to the serious status of nonpoint source pollution in Tai Lake area and forcing on studies of alternative agriculture on both home and abroad, carried on a field experiment in Liyang to find out an environmental farming systems in Tai Lake area. Compared the effects of conventional, special, organic and natural farming system on wheat yield, soil fertility properties and nutrients loss which provided suggestions for Tai Lake area to resolute the contraction between agricultural production and environmental protection.The study evaluated the effects of different farming systems on wheat growth, yield components and yield as well as discussed relationship among wheat growth, yield components and yield. The results showed that the yield in special farming system was highest, and convertional was higher than organic and natural farming system. Wheat yield in special farming system increased33.31%compared with the conventional one, course to the weight of a thousand grains and number of ears in conventional farming system was higher than other farming systems. Compared to conventional farming system, the yield in organic, natural farming system decreased19.57%and67.91%respectively, and there was a significant difference (P<0.05) between organic and conventional farming system. The a thousand grains in organic faming system was extremely higher (P<0.01) than conventional farming system, thus reduced the difference between them. In addition, the study found that the key point in wheat producing was weed and wheat density management during seeding stage of wheat.Study focused on soil physical properties, pH and nutrients contents. The results showed that, the soil fertility properties in organic farming system were the best in four farming systems, and conventional and natural farming systems were worst. Organic farming system maintained good soil porosity, water-holding capacity and soil pH. Meanwhile, organic farming system improved the soil nutrients content. For example, compared with conventional and special farming systems, the soil fertility was stable during the whole wheat growth period as well as organic matter, total nitrogen, available N and available P were increased7.70%,5.69%,10.50%and5.98%respectively under organic farming system.The effects of different farming systems on nutrients utilization and loss were though evaluation of nitrogen and phosphorus uptake by wheat, distribution on soil profile (0-20cm,20～40cm,40～60cm,60～80cm) and loss with runoff and lateral seepage. The results showed that nitrogen and phosphorus utilization in special farming system was higher than in organic and conventional farming systems, as meanwhile, the capacity of nutrients staged in soil of organic was better than special and conventional farming systems. Furthermore, the lowest risk of nutrients loss in organic farming system. For example, on one hand, the content of nitrogen and phosphorus accumulated in topsoil was more while was lower in20～80cm. On the other hand, nitrogen and phosphorus concentration was lower in runoff and lateral seepage in organic farming compared with other farming systems.In summary, conventional farming system should not be carried on in Tai Lake region as poor soil fertility and high risk of nutrients loss. Considered food security, natural farming system was not suitable, even though it was lower risk of nutrients loss. However, according to requirement of the environment and food security, organic and special farming system could develop in Tai Lake area due to the lower risk of nutrients loss, higher soil fertility and yield.