| Shaanxi Province is the largest region in the world.However,the content of soil organic matter in this area is relatively low,and low fertility.90% of the apple orchards have no irrigation conditions and the groundwater table is deep,and the farmers lack of scientific water and fertilizer management guidance.Serious imbalance in nutrient input,and less water conservation and preservation measures in the orchard have led to a continuous decline in orchard fertility and outstanding soil degradation problems,which has severely constrained the development of the apple industry.Therefore,the combination of orchard water and fertilizer measures will play a crucial role in improving the yield and quality of apple in dry land orchards.It is a comprehensive technology application which is combined the ground cover and balanced application of NPK fertilizer and organic fertilizer.The study of its effect on the orchard's hydrothermal conditions and apple yield and quality has become a research hotspot in recent years.In this study,we combined the orchard ground cover of plastic mulch and cover crop with the application of organic and inorganic fertilizers application technologies to explore the effects of three different managements on soil nutrient,water use efficiency,fruit tree growth,and apple yield,quality of Fuji apple orchard.In order to accomplish the goal of the high yield and quality of apples in the region,increase the quality and efficiency of chemical fertilizers,and efficient water use,which is intended to promote the development of apple orchards in dry land.The conclusions in this study are as follows:(1)The OM can significantly increase the spring shoot length,hundred leaves weight,and hundred leaves thickness,promote the growth and development of trees.In addition,OM can increase fruit firmness by 16.9% and 11.6% compared with FM and EM,respectively.And the excellent fruit rate is 25.0% higher than FM.The five-year average yield on OM has increased by 43.2% over the FM,and no significant difference with EM.Compared with FM,the net income of the OM is 83,100 yuan/ha which is 5 times that of the EM.(2)The effect of OM on soil organic carbon inter row is mainly concentrated in 0-40 cm soil layers,and in 0-20 cm soil layers in row.Compared with the FM,the EM and FM of the mulch treatment in row,the microbial carbon content in the 0-40 cm soil layer under the mulch was significantly higher than FM,and there was no significant difference in the 0-20 cm soil layer between the EM and FM,however,it is significantly higher than FM in 20-40 cm.The microbial carbon content of OM was significantly higher than that of FM in the 0-40 cm inter row.(3)Compared with the FM and EM,OM treatment could significantly increase soil water storage capacity in 0-200 cm soil layer,and water content of 0-100 cm soil layer was increased by 5.6% and 15.3% in the dry season compared with FM and EM treatment,respectively.Besides,the soil water relative deficit index of OM was lower than that of EM in 200-300 cm soil layer.The rainfall infiltration in the dry year could reach 300 cm depth under OM.Meanwhile,OM stabled soil water content,and efficiently alleviated the desiccation in deep soil layer.Compared with FM and EM,the 4-year average yield of OM was increased by 36.6% and 22.5%,respectively.(4)Both the EM and OM can promote the absorption and utilization of soil nitrogen by leaves and fruits,of which the OM of nitrate accumulation is mainly concentrated in the soil layer of 100~120cm,the accumulation layer moves upward clearly,compared with the FM.In addition,the nitrate nitrogen content in 0~140 cm soil layer under OM treatment is significantly higher than that in the other two models.The accumulation of nitrate nitrogen in the deep soil(200 to 300 cm)is significantly reduced,effectively reducing the accumulation in the deep soil.(5)The soil organic matter content in the 0-20 cm soil layer of the OM and the EM was increased by 21.4% and 12.1%,respectively,compared with the FM.The total nitrogen content of the OM is increased by 20.8% and 19.3% in 0~20cm soil,respectively,compared with the FM and the EM,no significant difference in 20~40cm.Soil available phosphorus in 0-20 cm soil layer,the OM and the EM increased by 61.8% and 64.0% respectively compared with the FM.There was no significant difference in the average content of available potassium in the three treatments for four years,and the FM is significantly higher than that in the FM in each year except 2016.(6)These results sugget that compared with the EM,OM can significantly improve soil fertility,soil water and heat conditions by combining dual coverage with organic and inorganic fertilizer application technology.Reduce soil moisture and nitrogen loss,effectively.Meanwhile the OM also can promote the development of fruit trees,improve apple quality and yield,effectively. |
PDF Full Text Request