Effect of Planting in Furrow and Whole Plasticfilm Mulching on Double Ridges on Improvement of Degraded Desert Grassland

[Objective] This study aimed to provide theoretical basis and technologies for the application of planting in furrow and whole plastic-film mulching on double ridges. [Method] The conventional method was used to re-seed the bunch Gramineous forage in the degraded desert grassland in Yanchi, Ningxia Hui Autonomous Region. Four kinds of conservation treatments, namely, ridging with black film mulching, ridging with transparent film mulching, ridging with no mulching and the flatplanting with no ridging and mulching were conducted to the forage to analyze the effects of each treatment on soil moisture and seedling growth. [Result] From July to November, the moisture contents of ridging with black film mulching, ridging with transparent film mulching, ridging with no mulching and the flatplanting were respectivery 9.88%, 9.24%, 8.75% and 8.13%, showing significant differences among the treatments; the survival rates of re-seeding forage were 96.2% , 93.4% , 45.6% and 28.3% , and the mulching treatment showed significant difference with the unmulching treatments in survival rate. The treatment with black film mulching showed great advantage that its moisture content on ridge top had the buffering effect of ＂load shifting＂, and the soil moisture content of black mulching treatment increased 21.5% than the flatplanting. Black film mulching also had the largest water supplement amount in soil below 1 m. Although mulching cost too much, its overall benefits were higher than that with no mulching. [Conclusion] This study lays the experimental basis for the application of planting in furrow and whole plastic-film mulching on double ridges in improving degraded grassland desertification.

Mechanism analysis and performance improvement of mechanized ridge forming of whole plastic film mulched double ridges

In order to achieve high-performance and mechanization construction standard of whole plastic mulched double ridge seedbed,and to meet its forming process and corresponding agronomic requirements of the mechanized double ridge seedbed,the key working parameters such as the speed of rotary blade group,the thickness of upturned sod and the power consumption of rotary blade group under different parameters were analyzed based on related working performance in ridge forming.Also,the test factors and their range of values were finally determined in this study.Discrete element method(DEM)simulation was applied in the numerical simulation of the mechanized ridge forming process of whole plastic mulched double ridges,and the ridge forming effect and digging resistance variation characteristics of different types of shovels were compared.Taking the forward speed of the combined machine,the penetration angle of the arc-shaped shovel and the depth of rotary tillage as independent variables,and the qualified rate of seedbed tillage as the response value,the mathematical model between the test factors and the qualified rate of the seedbed tillage was established,to explore the influence sequence of the factors on the qualified rate of seedbed tillage,and obtained the following optimal working parameters of the ridge forming device:the advancing velocity of the combined machine of 0.50 m/s,penetration angle of the arc-shaped shovel of 31°,rotary tillage depth of 140 mm,and average qualified rate 95.20%of seedbed tillage in corresponding simulation verification test.Field test showed that the average qualified rate of seedbed tillage in ridge forming device was 93.60%,which was close to that of the simulation results.The actual working condition of the sample machine was basically in line with the simulation process and could relatively precisely reflect the mechanized ridge forming mechanism of whole plastic double ridges.The results showed that the established DEM model and its parameter setting were relatively accurate and reasonable.