Endomycorrhizal fungi play an important role in the survival of plants on poor soils. Planting seeds into lunar soil at a lunar colony will be a challenge for seeds of any plant. The seeds will need a special microbi...Endomycorrhizal fungi play an important role in the survival of plants on poor soils. Planting seeds into lunar soil at a lunar colony will be a challenge for seeds of any plant. The seeds will need a special microbial “tool kit” that will help them germinate and the young seedlings establish themselves. In this study, seeds of the prickly pear cactus, Opuntia ficus-indica, were chosen to examine the presence of fungus spores in the soil, inside the seeds and after germination in the rhizosphere, roots and other tissues of the young seedlings. The nutrient poor lunar regolith simulant JSC-1A was used as autoclaved or untreated growth medium. The mycorrhizal fungus Trichoderma viride was predominantly identified on the roots of new seedlings. This fungus also demonstrated the strongest effect on the germination rate of the seeds in comparison with other fungi isolated from the rhizosphere of Opuntia plants. T. viride was not detected within seeds and also not within seedlings, besides the root tips, whereas an arbuscular mycorrhizal Glomus species was seed-borne and present throughout most of the seedling. A close association between T. viride and a Glomus species associated with O. ficus-indica is demonstrated through light microscopic and electron microscopic images of the outside and inside root tips of the seedlings.展开更多
Cultivating traditional upland rice cultivars on nutrient depleted soil causes poor and low yield. Little attention is paid to performance of inter-specific NERICA cultivars grown on nutrient deficient soil augmented ...Cultivating traditional upland rice cultivars on nutrient depleted soil causes poor and low yield. Little attention is paid to performance of inter-specific NERICA cultivars grown on nutrient deficient soil augmented with different types of compost. Therefore, field trials were conducted during 2010 and 2011 planting seasons in Ibadan to evaluate growth, dry matter, nutrient uptake efficiency and grain yield of upland rice grown on nutrient deficient soil augmented with different types of compost. There were nine treatments comprising of three upland rice cultivars: NERICA I, NERICA II and Ofada, two compost types applied at the rate of 8 t·ha-1: poultry dropping + maize stover (PDMC) and cattle dung + maize stover (CDMC) and control. The treatments were laid out in randomized complete block design and replicated three times. CDMC enhanced growth, nutrient use efficiency, dry matter and grain yield of upland rice cultivars. Performance of Ofada was better than NERICA cultivars. N (24.55 g), P (12.45 g) and K (35.41 g) uptake concentration and grain yield (5.45 t/ha) were highest in Ofada plots augmented with CDMC. Residual effect of compost on growth, yield and nutrient uptake efficiency of upland rice on nutrient deficient soil was marginal.展开更多
Legume plants are an essential component of sustainable farming systems.Phosphorus(P) deficiency is a significant constraint for legume production, especially in nutrient-poor soils of arid and semi-arid regions.In th...Legume plants are an essential component of sustainable farming systems.Phosphorus(P) deficiency is a significant constraint for legume production, especially in nutrient-poor soils of arid and semi-arid regions.In the present study, we conducted a pot experiment to evaluate the effects of a phosphorus-mobilizing plant-growth promoting rhizobacterial strain Bacillus cereus GS6, either alone or combined with phosphate-enriched compost(PEC) on the symbiotic(nodulation-N_2 fixation) performance of soybean(Glycine max(L.) Merr.) on an Aridisol.The PEC was produced by composting food waste with addition of single super phosphate.The bacterial strain B.cereus GS6 showed considerable potential for P solubilization and mobilization by releasing carboxylates in insoluble P(rock phosphate)-enriched medium.Inoculation of B.cereus GS6 in combination with PEC application significantly improved nodulation and nodule N_2 fixation efficiency.Compared to the control(without B.cereus GS6 and PEC), the combined application of B.cereus GS6 with PEC resulted in significantly higher accumulation of nitrogen(N), P, and potassium(K) in grain, shoot, and nodule.The N:P and P:K ratios in nodules were significantly altered by the application of PEC and B.cereus GS6, which reflected the important roles of P and K in symbiotic performance of soybean.The combined application of PEC and B.cereus GS6 also significantly increased the soil dehydrogenase and phosphomonoesterase activities, as well as the soil available N, P, and K contents.Significant positive relationships were found between soil organic carbon(C) content, dehydrogenase and phosphomonoesterase activities, and available N, P, and K contents.This study suggests that inoculation of P-mobilizing rhizobacteria, such as B.cereus GS6, in combination with PEC application might enhance legume productivity by improving nodulation and nodule N_2 fixation efficiency.展开更多
Aims Mongolian pine(Pinus sylvestris var.mongolica)and Xiaozhuan poplar(Populus×xiaozhuanica)are two predominant afforestation tree species in the semi-arid sandy lands of northeast china,which are characterized ...Aims Mongolian pine(Pinus sylvestris var.mongolica)and Xiaozhuan poplar(Populus×xiaozhuanica)are two predominant afforestation tree species in the semi-arid sandy lands of northeast china,which are characterized by poor soil nutrients.Plant litter decomposition plays a critical role in regulating nutrient cycling in terrestrial ecosystems.Admixture of broadleaf litter to conifer litter is expected to improve litter decomposition and soil fertility,and thus productivity.However,the effects on the decomposition of litter mixture of the above two tree species are not well understood.therefore,it is essential to assess the decomposition performance of litter mixture with the aim of improving forest nutrient management and the establishment of mixed plantation.Appropriate forest manage-ment practice is critical for the sustainability of site productivity in plantation forests.Methods We conducted a field litterbag decomposition transplant experi-ment for single pine litter,single poplar litter and their mixture in a pine stand,a poplar stand and an adjacent grassland for 16 months in the Keerqin Sandy Lands,northeast china.Important Findings After 16 months of incubation,there remained significantly more litter mass of pine(73.8%)than of poplar(67.2%).the mass remaining was positively correlated with litter carbon(c):nitrogen(N),c:phosphorus(P)and lignin:N ratios,and negatively with litter N and P concentrations,which suggests that initial litter chemical properties were an important factor affecting litter decay.Generally,net N and P immobilizations were observed during decomposition.this indicates that litter decomposition in this area was N-limited as N was progressively immobilized,and then tended to induce P limitation.thus,we strongly recommend prohibiting litter harvesting by local residents to maintain soil fertility in this nutrient-poor area.Our results do not support the home-field advantage hypothesis,as illustrated by the fact that,in most cases,mass loss of litter from native habitat was comparable to that in transplanted habitats during decomposition.Furthermore,a dominant additive effect was detected,indicating that the establishment of mixed plantation may not be appropriate for these two species.展开更多
文摘Endomycorrhizal fungi play an important role in the survival of plants on poor soils. Planting seeds into lunar soil at a lunar colony will be a challenge for seeds of any plant. The seeds will need a special microbial “tool kit” that will help them germinate and the young seedlings establish themselves. In this study, seeds of the prickly pear cactus, Opuntia ficus-indica, were chosen to examine the presence of fungus spores in the soil, inside the seeds and after germination in the rhizosphere, roots and other tissues of the young seedlings. The nutrient poor lunar regolith simulant JSC-1A was used as autoclaved or untreated growth medium. The mycorrhizal fungus Trichoderma viride was predominantly identified on the roots of new seedlings. This fungus also demonstrated the strongest effect on the germination rate of the seeds in comparison with other fungi isolated from the rhizosphere of Opuntia plants. T. viride was not detected within seeds and also not within seedlings, besides the root tips, whereas an arbuscular mycorrhizal Glomus species was seed-borne and present throughout most of the seedling. A close association between T. viride and a Glomus species associated with O. ficus-indica is demonstrated through light microscopic and electron microscopic images of the outside and inside root tips of the seedlings.
文摘Cultivating traditional upland rice cultivars on nutrient depleted soil causes poor and low yield. Little attention is paid to performance of inter-specific NERICA cultivars grown on nutrient deficient soil augmented with different types of compost. Therefore, field trials were conducted during 2010 and 2011 planting seasons in Ibadan to evaluate growth, dry matter, nutrient uptake efficiency and grain yield of upland rice grown on nutrient deficient soil augmented with different types of compost. There were nine treatments comprising of three upland rice cultivars: NERICA I, NERICA II and Ofada, two compost types applied at the rate of 8 t·ha-1: poultry dropping + maize stover (PDMC) and cattle dung + maize stover (CDMC) and control. The treatments were laid out in randomized complete block design and replicated three times. CDMC enhanced growth, nutrient use efficiency, dry matter and grain yield of upland rice cultivars. Performance of Ofada was better than NERICA cultivars. N (24.55 g), P (12.45 g) and K (35.41 g) uptake concentration and grain yield (5.45 t/ha) were highest in Ofada plots augmented with CDMC. Residual effect of compost on growth, yield and nutrient uptake efficiency of upland rice on nutrient deficient soil was marginal.
基金financially supported by the Agricultural Linkages Programme (ALP) of Pakistan Agricultural Research Council (PARC) (ALP/PARC) (No.CS-268) on Microbial Biotechnology for Sustainable Production of LegumesProf.Dr.Zahir A.Zahir, Soil Microbiology & Biochemistry Laboratory, Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Pakistan, for providing financial and logistic support to carry out the present investigation
文摘Legume plants are an essential component of sustainable farming systems.Phosphorus(P) deficiency is a significant constraint for legume production, especially in nutrient-poor soils of arid and semi-arid regions.In the present study, we conducted a pot experiment to evaluate the effects of a phosphorus-mobilizing plant-growth promoting rhizobacterial strain Bacillus cereus GS6, either alone or combined with phosphate-enriched compost(PEC) on the symbiotic(nodulation-N_2 fixation) performance of soybean(Glycine max(L.) Merr.) on an Aridisol.The PEC was produced by composting food waste with addition of single super phosphate.The bacterial strain B.cereus GS6 showed considerable potential for P solubilization and mobilization by releasing carboxylates in insoluble P(rock phosphate)-enriched medium.Inoculation of B.cereus GS6 in combination with PEC application significantly improved nodulation and nodule N_2 fixation efficiency.Compared to the control(without B.cereus GS6 and PEC), the combined application of B.cereus GS6 with PEC resulted in significantly higher accumulation of nitrogen(N), P, and potassium(K) in grain, shoot, and nodule.The N:P and P:K ratios in nodules were significantly altered by the application of PEC and B.cereus GS6, which reflected the important roles of P and K in symbiotic performance of soybean.The combined application of PEC and B.cereus GS6 also significantly increased the soil dehydrogenase and phosphomonoesterase activities, as well as the soil available N, P, and K contents.Significant positive relationships were found between soil organic carbon(C) content, dehydrogenase and phosphomonoesterase activities, and available N, P, and K contents.This study suggests that inoculation of P-mobilizing rhizobacteria, such as B.cereus GS6, in combination with PEC application might enhance legume productivity by improving nodulation and nodule N_2 fixation efficiency.
基金This study was funded by the National Natural Science Foundation of China(31870603 and 31270668).
文摘Aims Mongolian pine(Pinus sylvestris var.mongolica)and Xiaozhuan poplar(Populus×xiaozhuanica)are two predominant afforestation tree species in the semi-arid sandy lands of northeast china,which are characterized by poor soil nutrients.Plant litter decomposition plays a critical role in regulating nutrient cycling in terrestrial ecosystems.Admixture of broadleaf litter to conifer litter is expected to improve litter decomposition and soil fertility,and thus productivity.However,the effects on the decomposition of litter mixture of the above two tree species are not well understood.therefore,it is essential to assess the decomposition performance of litter mixture with the aim of improving forest nutrient management and the establishment of mixed plantation.Appropriate forest manage-ment practice is critical for the sustainability of site productivity in plantation forests.Methods We conducted a field litterbag decomposition transplant experi-ment for single pine litter,single poplar litter and their mixture in a pine stand,a poplar stand and an adjacent grassland for 16 months in the Keerqin Sandy Lands,northeast china.Important Findings After 16 months of incubation,there remained significantly more litter mass of pine(73.8%)than of poplar(67.2%).the mass remaining was positively correlated with litter carbon(c):nitrogen(N),c:phosphorus(P)and lignin:N ratios,and negatively with litter N and P concentrations,which suggests that initial litter chemical properties were an important factor affecting litter decay.Generally,net N and P immobilizations were observed during decomposition.this indicates that litter decomposition in this area was N-limited as N was progressively immobilized,and then tended to induce P limitation.thus,we strongly recommend prohibiting litter harvesting by local residents to maintain soil fertility in this nutrient-poor area.Our results do not support the home-field advantage hypothesis,as illustrated by the fact that,in most cases,mass loss of litter from native habitat was comparable to that in transplanted habitats during decomposition.Furthermore,a dominant additive effect was detected,indicating that the establishment of mixed plantation may not be appropriate for these two species.
