The Export And Evaluation About Material And Nutrients Of Pasture Under The Walnut And Grass Pattern

In recent years,with the implementation of the policy of returning farmland to forest,afforestation area in our country was increasing day by day.But,there were some inefficient stand,need to be modified to enhance its function and efficiency.Therefore,people transformed Kashiwagi(Cupressus funebris Endl.)inefficient forest and replaced tree species,developed a lot of walnut(Juglans regia L.)economic forest industry in the hilly area of central Sichuan,but in the early stages of planting walnut,the open space of the forest was large,leading to the low land use efficiency in the early period of afforestation,which made the soil moisture evaporate seriously and the soil erosion in the rainy season was serious,The growth of weeds affect the growth and development of walnut and weeds in addition to the higher cost.In order to solve these problems,it was necessary to introduce some plants on the walnut forest land,and forage grass,which grows fast,the root system was very strong,the harvest could be regenerated after harvest,and it has economic,social and ecological benefits.Therefore,this study through the walnut trees were intercropping Cichorium intybus and Medicago sativa and other eight kinds of forage in Deyang Jingyang District,then the adaptability of different grasses in the walnut trees in this area was observed and compared;and to explore the dynamises of pasture yield,mineral nutrient and nutrient composition,and comprehensive evaluation to select the appropriate forage,which were planted under walnut trees.Providing a reference for the development of the economy,forest grass model grass selection and field nutrient management.The results were mainly as follows:(1)During the winter season,Trifolium pratense and Astragalus adsurgens were not able to survive,because it was so cold and dry during the winter;the next year from May to June,better water and heat conditions but the soil compaction,so Lolium perenne and Elymus dahuricus,which grow slowly;July to September,the rain caused more water,leading to Melilotus officinalis dead,because their roots were rot.Therefore,according to the adaptation of pasture to the climatic environment of the area,the forage varieties were eliminated.According to the comparison of the root system and aboveground part of the plant before and after wintering,the root system of Cichorium intybus and other grasses was strong,which was helpful to cold and drought resistance;and Melilotus officinalis could be used as short-term with forage grass.(2)As a result of the growth of the root system,the first year of forage was mowed four times,the second year was 5 times;the annual yield of fresh,Cichorium intybus>Medicago sativa>Dactylis glomerata,and the difference was significant;and the annual yield of Medicago sativa and Cichorium intybus were significantly higher than that of Dactylis glomerata;and the yield of fresh hay of Medicago sativa and Cichorium intybus were higher in the period from May to July,and the yield of Dactylis glomerata was smaller in this period.But,the dynamics of forage grass and hay yield wasn't consistent.(3)The mineral nutrient content of grass under the young forest was as follows:The total N content of Dactylis glomerata and Cichorium intybus increased first and then increased,then stabilized,and Medicago sativa was significantly higher than that of Dactylis glomerata and Cichorium intybus in each period;the total P content of Dactylis glomerata and Cichorium intybus showed double peak and double valleys;but,the dynamic law of the total K content of Medicago sativa was not obvious,and it was lower than the content of Cichorium intybus and Dactylis glomerata,so,Medicago sativa required less K elements in the accumulation of unit mass dry matter process.Nutrient output dynamic performance as follows:In addition to the total Ca,the other nutrient elements of the annual output law was same as hay yield law;the nutrient output of pasture was concentrated in the growing season,but the dynamic output of various nutrient was quite different.(4)The regularity of nutrient content of pasture under young forest:The second year of Medicago sativa,Dactylis glomerata,and Cichorium intybus,which were better quality than first year;the highest content of CP was the highest in the first cutting,the lowest CF content,so the first crop of grass CP highest and palatability was good;the CP content of Medicago sativa in each period was higher than others,the content of CF in Cichorium intybus was lower,while the dynamic law of EE,ash and NFE was not obvious.The nutrient output was as follows:The dynamic law of each index was quite different,and the output of ash and NFE had a certain response with climatic factors.According to the annual output could be seen,that Medicago sativa was good protein forage,and Cichorium intybus was good forage grass by providing energy.(5)According to the adaptive screening and comprehensive evaluation,only three species were suitable for planting under the young walnut trees in the 8 kinds of forage.The evaluation results of comprehensive production performance were Medicago sativa>Medicago sativa>Dactylis glomerata.So,Cichorium intybus was the best choice under the walnut young forest,and Medicago sativa was second choice with better hay yield and better quality of CP.