Technology Of Grass-shrub Optimal Configuration And Hea Lthybreeding Of Cattle And Sheep In The Karst Desertification Environment

The karst area of southern China is extensive,with serious soil and water loss,serious contradiction between man and land,low vegetation coverage,an adverse succession trend in the ecosystem,and then it is occurred rocky desertification.It is the region with the most typical karst development and the most concentrated distribution in the world,it is also an area with fragile ecological environment and lagged economic development.In recent years,according to the rocky desertification control and the regional economic development,a lot of work has been carried out,such as planting economic fruit forest and forage,raising cattle,sheep and livestock,however,due to the extensive management methods,unreasonable allocation structure of grass-shrub and planting single economic forest in successive years which has caused that soil fertility and productivity gradually declined,and economic benefits continued to decreased.Therefore,studying on the optimum spatial allocation of grass-shrub and the healthy breeding techniques of cattle and sheep are used to make full use of the barren hills and slopes in rocky desertification areas,improve the utilization efficiency of land resources,carry out diversified three-dimensional planting,maintain soil nutrient balance,maintain soil nutrient balance,promote the high quality and high efficiency production of forage resources and the development of grassland animal husbandry,it is necessary to realize the coordinated development of planting grass and raising livestock,rocky desertification control and ecological benefits,economic and social benefits,and promote regional poverty alleviation.Based on the theoretical basis of natural geography,botany,ecology,soil science,and ecological breeding theory,this study selected Guanling-Zhenfeng demonstration area with modium-intensive rocky desertification of karst plateau-canyon in Huajiang and Salaxi demonstration area with potential-light rocky desertification of karst plateau-mountain in Bijie.the theoretical basis,mechanism,key technology and technology integration for the optimal allocation of grass-shrub and healthy breeding of cattle and sheep were studied in the karst rocky desertification environment through the method of literature review,field investigation,laboratory test,quantitative and qualitative analysis.1.Under the condition of balanced nutrient allocation,the intercropping yield of grass-shrub is generally higher than that of single cropping in rocky desertification area.In the Huajiang demonstration area,only the intercropping yield of Pennisetum sinese and Hylocereus undatus(Haw.)Britt.et Rose is lower than that single cropping of Pennisetum sinese,the average fresh grass yield for the rest of the mixed planting of grass-shrub is 36840 kg/hm~2,and the hay yield is6812.5 kg/hm~2,which is 15.9%and 16.5%higher than the average fresh grass yield and hay yield for single cropping respectively(except for Pennisetum sinese).In Salaxi demonstration area,the average fresh grass yield for the mixed planting of grass-shrub is 42261.3kg/hm~2,and the hay yield is 7797kg/hm~2,which is 4.0%and 2.2%higher than the average fresh grass yield and hay yield for single cropping respectively.2.The nutritional value of artificial planting for grass-shrub in different grade rocky desertification areas is different.Medicago sativa L.is best and Pennisetum sinese is worst in the Huajiang demonstration area,Trifolium repens L.is best and Dactylis glomerata L.is worst In Salaxi demonstration area.While its optimal allocation is also different.Sophora davidii(Franch.)Skeels),Medicago sativa L.and Hemarthria compressa(L.f.)R.Br is the optimal allocation in the Huajiang demonstration area,the combination planting of Amorpha fruticosa Linn,Trifolium repens L.and Lolium perenne L.is the best way to meet the conditions of suitable land and the optimal allocation of healthy breeding for cattle and sheep in Salaxi demonstration area.In the future work,we should strengthen the utilization of grass-shrub variety resources,combine with the construction of sample land for artificial grass-shrub,and form a relatively balanced nutrition pattern of cattle and sheep,which is dominated by high-quality grass-shrub resources and supplemented by concentrate supplement.3.The yield benefit of mixed sowing in two demonstration areas is higher than single cropping,and the yield benefit of complex mixed sowing is higher than that of simple mixed sowing,while the mixed sowing of leguminosae and gramineae is higher than the mixed sowing of other families and genera.The reasonable collocation of feeding shrub,leguminous forage and gramineous forage can efficiently play to the nutritive value of different grass-shrub varieties.Therefore,it is necessary to make full use of this rule in the process of grass-shrub construction in rocky desertification area to strengthen the development and utilization of more high-quality and suitable feeding shrub varieties and plant leguminosae and gramineae forage to meet the nutritional needs of cattle and sheep.4.Under the condition of different grade rocky desertification environment,the soil organic matter content is significantly increased by different grass-shrub allocation mode(P<0.05).In the Huajiang demonstration area,the combination of Pennisetum sinese Roxb and Hylocereus undulatus Britt,the combination of Zanthoxylum bungeanum Maxim and Medicago sativa L.and the control experiment show that total nitrogen content,total phosphorus content,effective phosphorus content,total potassium content and organic matter content of the soil are increased significantly(P<0.05).In the Salaxi demonstration area,the combination of Juglans regia,Dactylis glomerata L.and Trifolium repens L.,the combination of Pyrus spp,Lolium perenne L.and Trifolium repens L.and the control experiment show that pH value and organic matter content of the soil are significantly increased under different allocation patterns of grass-shrub(P<0.05).5.Feeding cattle and sheep with high quality forage in rocky desertification area has great economic benefits.According to the cost of artificial management,feed,medicine,slaughtering rate and meat price,the profit of cattle is about 3086.34 yuan per head,and the profit of sheep is about 412.5 yuan per head.Considering the difference in feeding scale and economic benefit of cattle and sheep,feeding sheep with moderate scale according to the grassland area has higher economic benefits than cattle breeding.