Effects Of Fertilizer Reduction Combined With Garden Waste Compost On The Growth,Yield And Soil Fertility Of Barley

As the main food crop in the plateau area,highland barley is also the main source of income increase for farmers and herdsmen.Due to the long-term application of large amounts of chemical fertilizer,the neglect of the application of organic fertilizer in agricultural production,the increase of production cost and the decline of soil quality and other problems,the yield and quality of highland barley decline.Research shows that garden waste compost combined with fertilizer can effectively improve crop yield and quality.At the same time improve soil physical and chemical properties,improve soil fertility.In order to further explore the effects of fertilizer reduction combined with garden waste compost on the yield,quality and soil fertility of highland barley,11 treatments were designed in the field experiment,including blank no fertilizer（CK）,total fertilizer:urea150 kg·hm^-2+diammonium phosphate 225 kg·hm^-2（CF）and total garden waste compost:8000 kg·hm^-2（GWC）was the control,90%total fertilizer+garden waste compost 6000 kg·hm^-2（A1）,80%total fertilizer+garden waste compost8000 kg·hm^-2（A2）,70%total fertilizer+garden waste compost 10000 kg·hm^-2（A3）,60%Total fertilizer+garden waste compost 12000 kg·hm^-2（A4）,90%total fertilizer+garden waste compost 8000 kg·hm^-2（B1）,80%total fertilizer+garden waste compost 8000 kg·hm^-2（B2）,70%total fertilizer+garden waste compost8000 kg·hm^-2（B3）,60%total fertilizer+garden waste compost 8000 kg·hm^-2（B4）.Through the effects of single fertilizer application and fertilizer reduction combined with garden waste compost on the yield,quality and soil fertility of highland barley,the optimal application amount of fertilizer reduction combined with garden waste compost was determined,in order to provide theoretical and practical basis for the increase of highland barley,soil improvement and garden waste resource utilization on the Qinghai-Tibet Plateau.The main conclusions are as follows:（1）Pot experiment showed that fertilizer reduction combined with garden waste compost could promote the development of plant height,chlorophyll,biomass and root system of highland barley seedlings.The chlorophyll content of B1(27.69 mg·g^-1)and root length（21.69 cm）were significantly higher than those of other treatments（P<0.05）.The root volume of B3（3.70 cm³）was significantly higher than that of other treatments（P<0.05）,and the strong seedling index of A3（0.22）was significantly higher than that of other treatments（P<0.05）.With the decrease of fertilizer（group A）and the increase of garden waste compost（group B）,the soil bulk density and p H were effectively reduced,and the contents of porosity,water content,EC and organic matter were increased.Compared with the total nitrogen and total potassium of CF soil,the available nutrients and total phosphorus decreased,and the enzyme activity also decreased.Through comprehensive evaluation of all treatments,B3 treatment had the highest evaluation（1.68）,and single fertilizer application had the lowest evaluation（0.33）compared with other treatments,indicating that appropriate reduction of fertilizer application and adding garden waste compost could effectively promote the growth of highland barley seedlings.（2）Through field experiments,it is concluded that fertilizer reduction combined with garden waste compost can effectively improve the yield of highland barley,and A2 treatment（same as B2 treatment）has the highest yield(3601.80 kg·hm^-2),while other treatments have different degrees of reduction compared with CF treatment,indicating that fertilizer reduction of 10～20%combined with garden waste compost is feasible.Adding garden waste compost treatment can effectively increase the soluble sugar content of barley and reduce crude fat,but it has negative effects on crude fiber,crude protein and starch.Adding garden waste compost can effectively increase soil nutrient content.According to the comprehensive evaluation of all treatments,A1 treatment had the highest evaluation（2.52）,and fertilizer application alone had the lowest evaluation（-0.93）compared with other treatments,indicating that appropriate reduction of fertilizer consumption and adding garden waste compost could bring economic benefits.