Intercropping of mulberry(Morus alba L.)and alfalfa(Medicago sativa L.)is a new forestry-grass compound model in China,which can provide high forage yields with high protein.Nitrogen application is one of the importan...Intercropping of mulberry(Morus alba L.)and alfalfa(Medicago sativa L.)is a new forestry-grass compound model in China,which can provide high forage yields with high protein.Nitrogen application is one of the important factors determining the production and quality of this system.To elucidate the advantages of intercropping and nitrogen application,we analyzed the changes of physicochemical properties,enzyme activities,and microbial communities in the rhizosphere soil.We used principal components analysis(PCA)and redundancy discriminators analysis to clarify the relationships among treatments and between treatments and environmental factors,respectively.The results showed that nitrogen application significantly increased pH value,available nitrogen content,soil water content(SWC),and urea(URE)activity in rhizosphere soil of monoculture mulberry.In contrast,intercropping and intercropping+N significantly decreased pH and SWC in mulberry treatments.Nitrogen,intercropping and intercropping+N sharply reduced soil organic matter content and SWC in alfalfa treatments.Nitrogen,intercropping,and intercropping+N increased the values of McIntosh diversity(U),Simpson diversity(D),and Shannon-Weaver diversity(H’)in mulberry treatments.However,PC A scatter plots showed clustering of monoculture mulberry with nitrogen(MNE)and intercropping mulberry without nitrogen(M0).Intercropping reduced both H’and D but nitrogen application showed no effect on diversity of microbial communities in alfalfa.There were obvious differences in using the six types of carbon sources between mulberry and alfalfa treatments.Nitrogen and intercropping increased the numbers of sole carbon substrate in mulberry treatments where the relative use rate exceeded 4%.While the numbers declined in alfalfa with nitrogen and intercropping.RDA indicated that URE was positive when intercropping mulberry was treated with nitrogen,but was negative in monoculture alfalfa treated with nitrogen.Soil pH and SWC were positive with mulberry treatments but were negative with alfalfa treatments.Intercropping with alfalfa benefited mulberry in the absence of nitrogen application.Intercropping with alfalfa and nitrogen application could improve the microbial community function and diversity in rhizosphere soil of mulberry.The microbial community in rhizosphere soil of mulberry and alfalfa is strategically complementary in terms of using carbon sources.展开更多
After five years of study,it was found that compared with the conventional cultivation techniques,the average yield per plant of3-5-year-old Jinhong apple trees cultivated under the ridge covering mode was increased b...After five years of study,it was found that compared with the conventional cultivation techniques,the average yield per plant of3-5-year-old Jinhong apple trees cultivated under the ridge covering mode was increased by 2. 12 times,the stem diameter was increased by20%,the branch number was increased by 73. 5%,and the underground root number was increased by 38. 3%. Under the ridge covering mode,the main distribution area of the underground roots of Jinhong apple trees was moved down to 15-55 cm,the temperature of soil 20 cm beneath the surface of the ridges increased by 1. 3-1. 5℃,the temperature of soil 40 cm beneath the surface of the ridges rose by 0. 9-1. 0℃,and the water content of soil 20-40 cm from the ground was maintained around 5%. Under the ridge covering mode,the Jinhong apple trees grew robustly,began to fruit 3 years later and yielded highly 5 years later. In addition,the ridge covering model also has illumination-enhancing,pest-controlling and tillage-free characteristics.展开更多
基金the Heilongjiang Province Science Foundation for Youths(Grant No.QC2016018)the National Natural Science Foundation of China(Grant No.31600508)+2 种基金the Fundamental Research Funds for the Central University(2572017CA21)the Application Technology Research and Development Projects of Heilongjiang Province(Grant No.WB13B104)the Science and Technology Project of Heilongjiang Farms&Land Reclamation Administration(Grant No.HNK135-01-056)。
文摘Intercropping of mulberry(Morus alba L.)and alfalfa(Medicago sativa L.)is a new forestry-grass compound model in China,which can provide high forage yields with high protein.Nitrogen application is one of the important factors determining the production and quality of this system.To elucidate the advantages of intercropping and nitrogen application,we analyzed the changes of physicochemical properties,enzyme activities,and microbial communities in the rhizosphere soil.We used principal components analysis(PCA)and redundancy discriminators analysis to clarify the relationships among treatments and between treatments and environmental factors,respectively.The results showed that nitrogen application significantly increased pH value,available nitrogen content,soil water content(SWC),and urea(URE)activity in rhizosphere soil of monoculture mulberry.In contrast,intercropping and intercropping+N significantly decreased pH and SWC in mulberry treatments.Nitrogen,intercropping and intercropping+N sharply reduced soil organic matter content and SWC in alfalfa treatments.Nitrogen,intercropping,and intercropping+N increased the values of McIntosh diversity(U),Simpson diversity(D),and Shannon-Weaver diversity(H’)in mulberry treatments.However,PC A scatter plots showed clustering of monoculture mulberry with nitrogen(MNE)and intercropping mulberry without nitrogen(M0).Intercropping reduced both H’and D but nitrogen application showed no effect on diversity of microbial communities in alfalfa.There were obvious differences in using the six types of carbon sources between mulberry and alfalfa treatments.Nitrogen and intercropping increased the numbers of sole carbon substrate in mulberry treatments where the relative use rate exceeded 4%.While the numbers declined in alfalfa with nitrogen and intercropping.RDA indicated that URE was positive when intercropping mulberry was treated with nitrogen,but was negative in monoculture alfalfa treated with nitrogen.Soil pH and SWC were positive with mulberry treatments but were negative with alfalfa treatments.Intercropping with alfalfa benefited mulberry in the absence of nitrogen application.Intercropping with alfalfa and nitrogen application could improve the microbial community function and diversity in rhizosphere soil of mulberry.The microbial community in rhizosphere soil of mulberry and alfalfa is strategically complementary in terms of using carbon sources.
基金Supported by Earmarked Fund for China Agriculture Research System(CARS-27)
文摘After five years of study,it was found that compared with the conventional cultivation techniques,the average yield per plant of3-5-year-old Jinhong apple trees cultivated under the ridge covering mode was increased by 2. 12 times,the stem diameter was increased by20%,the branch number was increased by 73. 5%,and the underground root number was increased by 38. 3%. Under the ridge covering mode,the main distribution area of the underground roots of Jinhong apple trees was moved down to 15-55 cm,the temperature of soil 20 cm beneath the surface of the ridges increased by 1. 3-1. 5℃,the temperature of soil 40 cm beneath the surface of the ridges rose by 0. 9-1. 0℃,and the water content of soil 20-40 cm from the ground was maintained around 5%. Under the ridge covering mode,the Jinhong apple trees grew robustly,began to fruit 3 years later and yielded highly 5 years later. In addition,the ridge covering model also has illumination-enhancing,pest-controlling and tillage-free characteristics.
