| Green manure is one of the important Chinese traditional organic fertilizer.In order to fully play the role of green manure in increasing production,the yield and quality of green manure,the proper use of green manure must be guaranteed.Different regulation of water and fertilizer,different planting mode with crops will affect the growth of green manure.Here,a high-efficiency nitrogen-fixing microorganism was isolated,further combined with IAA-producing strain(Bacillus megaterium)or pea rhizobia strains(Rhizobium legminosarum),and pot experiments were set to evaluate the effects of those microbial agents for different green manure.At the same time,typical dry land agricultural region Wuchuan Inner Mongolia was chosen as the study area due to its water limitation and one crop a year planting system.Based on the idea of repairing while producing,different water irrigation measurements,potato monoculture and potato intercropping Vicia villosa were set to study the effects of water regulation and planting patterns on potato growth and soil quality,which provides a reference for establishing a reasonable model of green manure planting.The main results are as follows:1.A strain N3 with strong nitrogen fixation ability has been selected from the farmland soil in Tai ’an.Shandong province.It was identified as Bacillus megaterium based on the morphological,physiological and biochemical characteristics and 16S rDNA gene sequences analysis.And its nitrogenase activity was up to C2H4 28.33 nmol/(h·mL).2.The effects of nitrogen fixation strain N3 and IAA-producing strain CDL29(Pantoea agglomerans)on the growth promotion of Orychophragmus violaceus and soil quality were studied in pot culture.Four treatments were set,including single or double inoculation of nitrogen fixation strain N3 or IAA-producing strain CDL29,plant without any inoculation set as the control treatment(CK).The results showed that,all plant growth-promoting bacterium promoted the growth of Orychophragmus violaceus,and the treatment with single inoculation of nitrogen-fixing strain N3 was the best.At the same time,the content of nitrogen,phosphorus in shoots of the Orychophragmus violaceus,and the nitrogen,potassium content in the roots of the Orychophragmus violaceus were significantly increased by the single inoculation of nitrogen-fixing strain N3,which were 33.03%,55.56%and 29.87%,51.11%respectively improved compared with the CK treatment.Other treatments also promoted the content of nutrients in Orychophragmus violaceus,but the trends were not significant.The contents of soil organic matter,total nitrogen and available nutrients were significantly increased by single inoculation of nitrogen-fixing strain N3.The contents of soil microbial carbon and microbial nitrogen were increased by the inoculation of different plant probiotics,single inoculation of nitrogen-fixing strain N3 had the best effect followed by the single inoculation of IAA-producing stain CDL29 and compound inoculation.In addition,inoculation of nitrogen-fixing strain N3 can significantly increase soil nitrogenase activity,while inoculation of CDL29 had no significantly effe ct on soil nitrogenase activity.3.The effects of nitrogen fixation strain N3 and pea rhizobia strains on the growth promotion of Vicia villosa and soil quality were studied in pot culture.Five treatments were set,including single inoculation of N3,single inoculation of Vic5,single inoculation of GL9,and double inoculation of strain N3 and Vic5,plant without any inoculation set as the control treatment(CK).The results showed that all the inoculation treatments could increase the above-ground bio mass and promote root growth and development.Compound inoculation treatment had the best effect on promoting the growth of Vicia villosa.The above-ground biomass of Vicia villosa has increased by 110.87%compared with CK.At the same time,it can effectively improve soil organic matter,available nutrients and soil microbial carbon and nitrogen.Nodule number,nodule nitrogenase activity and soil nitrogenase activity of rhizobium inoculated with rhizobium were higher than those inoculated with nitrogen-fixing strains.Meanwhile,the promotion of Vic5 inoculated single was better than that inoculated with GL9 single.4.In the Wuchuan Dry Farm Experimental Station,three water irrigation volumes including L(60 m3/667m2),M(120 m3/667m2),H(180 m3/667m2)and two planting modes e.g.potato monoculture and potato intercropping Vicia villosa were set to study cultivation management pattern effects on potato growth and soil fertility through drip irrigation.The results showed that potato intercropping Vicia villosa decreased potato production,compared with potato monoculture.Potato production was the largest under the potato monoculture with low irrigation treatment(PL)and under the intercropping with low irrigation treatment(GL)was.The under-ground biomass and nitrogen content of Vicia villosa was the highest with the irrigation volume of 120 m3/667m2.The potato production was the highest under the irrigation volume of 60 m3/667m2.The potato yield was not change with more irrigation.20 days after Vicia villosa incorporation,the content of soil organic matter,nutrient and soil microbial carbon and nitrogen were the highest(except total nitrogen)on the ridge under the intercropping with high irrigation treatment(GH(L)),the ammonium nitrogen and nitrate nitrogen content was significantly increased by 33.43%and 85.46%compared with those of the ridge under the monoculture with high irrigation treatment(PH(L)).In conclusion,potato intercropping Vicia villosa would decrease potato production,but Vicia villosa incorporation could significantly increase the soil organic matter and nutrient content as well as soil microbial carbon and nitrogen. |
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