Study On High Yield And Effective Techniques Of Sweetpotato Cultivation In The Hill Poor Dryland In South Of Shandong

This study was conducted in the hill poor dryland of southern Shangdong.Some problems existed in the hill poor dryland such as lower soil fertility and poor irrigated conditions,fewer variety and serious degradation,lower management level.To solve these problems,we did a number of cultivation test studies using jishu25 as test material.These studies included nurturing seedlings,application of high shear seedlings,suitable density,nitrogen fertilizer,potassium fertilizer,mulching,water saving cultivation and weed control in sweet potato field.The main results are as follows:1.In the condition of hill poor dryland,you can select some starchy varieties with some advantages such higher starch content,better resistance to barren soil and some plant diseases,etc.These varieties which jishu25,jishu21,shangshul9 and others were suitable for planting in Shandong hilly dryland.2.The time of nurturing seedling was generally before and after the spring equinox.Because Jishu25 had good germination,when nurturing seedlings,you can seclet this nursery way of flat row?In the density condition of 20.0kg/m2,tubers with about 100?250g weight were prior choice because these tubers can guarantee not only the number of potato seedlings but also seedling quality.3.Considering some factors such fresh yield,dry matter yield and economic.The suitable density of spring sweet potato was about 3300?3600/666.7m2 in the condition of Shandong hilly dryland.4.In the condition of hill poor dryland,soil nutrient content is generally about 40 mg/kg nitrogen,60 mg/kg available phosphorus,70 mg/kg available phosphorus and 1.0%organic matter.In the lower levels of fertility,the optimal fertilization program of jishu25 was 9.0 kg nitrogen,9.0?12.0kg potassium and 5.0kg phosphorus.This fertilization program can increase by more than 20%fresh potato yield than the program wiht no fertilizer.5.This study suggested that mulching can promote the early leaf growth;significantly improve tubers fresh weight of per plant,daily growth rate,root dry weight,fresh yield,marketable tuber yield and dry matter yield;reduce the T/R.Plastic mulching cultivation is an important measure to regulate reasonably the source-sink relationship in the middle-late of sweet potato growth,and black plastic mulching is better than the transparent plastic mulching6.The application of high shear seedlings is the commonly used method in the production of sweet potato.This study suggested that high shear planting seedlings could increase fresh yield by 20%and reduce 2.33 percentage points with significant differences than traditional pulling seedlings7.The high quality seedlings application with rooting powder could effectively guarantee the seedling survival rate,reduce the amount of water,and achieved the water saving cultivation.In the condition of 150ml watering,high quality seedlings application with rooting powder could improve effectively seedling survival rate and achieved 95.56%.8.The black plastic mulching is also safety measures to control weeds.30d after treated,the control efficacy on weeds of black plastic mulching was better with 89.28%.45d after treated,black plastic mulching and 33%pendimethalin EC had good control efficacy on weeds which were more than 90%.The use of plastic film mulching increased fresh tuber yields.Comparing with the CK,the treatment of black plastic mulching increased by 27.70%.The black plastic film cultivation can control the growth of weeds effectively,protect environment,save labor and promote light streamline production.