This study details soil’s physical and chemical properties in a rice-grown environment in Minna environs Niger State, Nigeria, under different soil and water conservation practices. Soil samples were collected at 0 -...This study details soil’s physical and chemical properties in a rice-grown environment in Minna environs Niger State, Nigeria, under different soil and water conservation practices. Soil samples were collected at 0 - 10 cm, 10 - 20 cm and 20 - 30 cm, respectively, using a soil auger to determine their physical and chemical properties such as moisture content, particle size, bulk density, particle density, porosity and organic matter. The textural classification determined the percentage dominance of the soil types in each study site location. The moisture content of site 1 ranged between 14.3% to 13.7%, site 2 ranged between 13.2% to 10.2%, site 3 ranged between 15.4% to 13.2%, site 4 ranged between 15.6% to 13.6% and site 5 ranged between 16.1% to 10.9%. The clay content of sites 3, 4 and 5 is higher than that of sites 1 and 2, while the silt contents of sites 1, 2 and 3 are higher than that of sites 4 and 5. The mean value of soil organic carbon from each study location was 2.37%, 2.03%, 2.43%, 2.07% and 2.17% for sites 1, 2, 3, 4, and 5, respectively. Therefore, site 1 is susceptible to erosion because of poor infiltration rate and well-ploughed or cultivated land by the tractor (harrowed). The particle sizes analysis indicated that the soil type in Site 1 and Site 2 is mainly sandy loam, while Site 3 and Site 5 are mainly loamy and predominantly clay loam in Site 4.展开更多
This research was designed to help solve existing sustainable use problems such as soil nutrient loss and soil fertility decline in natural rubber plantations located in the hilly land of the south central mountainous...This research was designed to help solve existing sustainable use problems such as soil nutrient loss and soil fertility decline in natural rubber plantations located in the hilly land of the south central mountainous area of Hainan Island, China. Two different land management practices, sustainable and traditional, were adopted in a four-year experiment. Contour terraced fields and deep ditches for green manure were built in a sustainable way with a balanced, need-based application of complex fertilizer. R…展开更多
为了解国内外人工林土壤地力的研究进展和发展趋势,采用文献计量学方法,以中国知网(CNKI)和Web of Science核心合集数据库相关文献为数据源,利用VOSviewer、HistCite等工具,从国家、机构、作者、研究热点方面对2021年之前的有关文献进...为了解国内外人工林土壤地力的研究进展和发展趋势,采用文献计量学方法,以中国知网(CNKI)和Web of Science核心合集数据库相关文献为数据源,利用VOSviewer、HistCite等工具,从国家、机构、作者、研究热点方面对2021年之前的有关文献进行了计量分析。结果表明:国内外该领域年发文量呈逐渐增长趋势,国际上发文量前3位的国家是中国、美国和巴西;中国最先在该领域进行研究且与国际的合作交流较多,文献总被引频次位居前列;国内该领域发文机构主要为涉林高校及中国科学院下属研究所,国际上美国俄亥俄州立大学发表的文献质量明显突出,引用频次较高;现阶段国内外在该领域的研究主要围绕土壤微生物群落组成、土壤养分含量以及与土壤地力维持的关系,但多处在定量描述阶段,很少涉及微生物功能代谢与人工林下有机物质周转以及对土壤地力维持的影响机制,研究深度亟待提升。总之,国内外同行合作交流、学科间交叉融合以及新生研究力量的补充是未来有效提升该研究领域的关键所在。展开更多
The processes of nutrient depletion and soil degradation within smallholder farms of central Kenya are spatially heterogeneous, determined by both biophysical and socio-economic factors. A monitoring study involving n...The processes of nutrient depletion and soil degradation within smallholder farms of central Kenya are spatially heterogeneous, determined by both biophysical and socio-economic factors. A monitoring study involving nutrient stocks, flows and balances was conducted in central Kenya to explore between and within-farm variability in soil fertility management and identify spatial niches for targeting soil fertility management strategies. Focus group discussions were conducted and farms grouped into 3 farm types （rich, medium and poor）. Nine case-study farms - three from each of the farm types - were randomly selected from the 50 farms studied, for detailed resource flow mapping. The farms were visited to record movement of nutrients inputs using a monitoring protocol covering soil, crops, livestock, and socio-economic aspects of the farm. Soil in different plots were sampled at a depth of 0-20 cm and analyzed for texture, pH, C, N, available P, exchangeable K＋, Mg2＋ and Ca2＋. Results revealed that wealthy farmers added an average of 51.3 kg/ha N, 37 kg/ha P, and 244 kg/ha K, compared to 25.9 kg/ha N, 14.5 kg/ha P and 50.7 kg/ha K for the poor farmers. In all farm types, home fields received more nutrient inputs compared to the outfields. Consequently, maize grain yields, partial nutrient balances and soil nutrient stocks were significantly higher in wealthy farms and home fields compared to poor farms and outfields, respectively. These results imply that different soil management strategies are required to achieve similar yields on the different field and farm types and avert soil degradation.展开更多
文摘This study details soil’s physical and chemical properties in a rice-grown environment in Minna environs Niger State, Nigeria, under different soil and water conservation practices. Soil samples were collected at 0 - 10 cm, 10 - 20 cm and 20 - 30 cm, respectively, using a soil auger to determine their physical and chemical properties such as moisture content, particle size, bulk density, particle density, porosity and organic matter. The textural classification determined the percentage dominance of the soil types in each study site location. The moisture content of site 1 ranged between 14.3% to 13.7%, site 2 ranged between 13.2% to 10.2%, site 3 ranged between 15.4% to 13.2%, site 4 ranged between 15.6% to 13.6% and site 5 ranged between 16.1% to 10.9%. The clay content of sites 3, 4 and 5 is higher than that of sites 1 and 2, while the silt contents of sites 1, 2 and 3 are higher than that of sites 4 and 5. The mean value of soil organic carbon from each study location was 2.37%, 2.03%, 2.43%, 2.07% and 2.17% for sites 1, 2, 3, 4, and 5, respectively. Therefore, site 1 is susceptible to erosion because of poor infiltration rate and well-ploughed or cultivated land by the tractor (harrowed). The particle sizes analysis indicated that the soil type in Site 1 and Site 2 is mainly sandy loam, while Site 3 and Site 5 are mainly loamy and predominantly clay loam in Site 4.
基金1Project supported by the United Nations Development Program.
文摘This research was designed to help solve existing sustainable use problems such as soil nutrient loss and soil fertility decline in natural rubber plantations located in the hilly land of the south central mountainous area of Hainan Island, China. Two different land management practices, sustainable and traditional, were adopted in a four-year experiment. Contour terraced fields and deep ditches for green manure were built in a sustainable way with a balanced, need-based application of complex fertilizer. R…
文摘为了解国内外人工林土壤地力的研究进展和发展趋势,采用文献计量学方法,以中国知网(CNKI)和Web of Science核心合集数据库相关文献为数据源,利用VOSviewer、HistCite等工具,从国家、机构、作者、研究热点方面对2021年之前的有关文献进行了计量分析。结果表明:国内外该领域年发文量呈逐渐增长趋势,国际上发文量前3位的国家是中国、美国和巴西;中国最先在该领域进行研究且与国际的合作交流较多,文献总被引频次位居前列;国内该领域发文机构主要为涉林高校及中国科学院下属研究所,国际上美国俄亥俄州立大学发表的文献质量明显突出,引用频次较高;现阶段国内外在该领域的研究主要围绕土壤微生物群落组成、土壤养分含量以及与土壤地力维持的关系,但多处在定量描述阶段,很少涉及微生物功能代谢与人工林下有机物质周转以及对土壤地力维持的影响机制,研究深度亟待提升。总之,国内外同行合作交流、学科间交叉融合以及新生研究力量的补充是未来有效提升该研究领域的关键所在。
文摘The processes of nutrient depletion and soil degradation within smallholder farms of central Kenya are spatially heterogeneous, determined by both biophysical and socio-economic factors. A monitoring study involving nutrient stocks, flows and balances was conducted in central Kenya to explore between and within-farm variability in soil fertility management and identify spatial niches for targeting soil fertility management strategies. Focus group discussions were conducted and farms grouped into 3 farm types （rich, medium and poor）. Nine case-study farms - three from each of the farm types - were randomly selected from the 50 farms studied, for detailed resource flow mapping. The farms were visited to record movement of nutrients inputs using a monitoring protocol covering soil, crops, livestock, and socio-economic aspects of the farm. Soil in different plots were sampled at a depth of 0-20 cm and analyzed for texture, pH, C, N, available P, exchangeable K＋, Mg2＋ and Ca2＋. Results revealed that wealthy farmers added an average of 51.3 kg/ha N, 37 kg/ha P, and 244 kg/ha K, compared to 25.9 kg/ha N, 14.5 kg/ha P and 50.7 kg/ha K for the poor farmers. In all farm types, home fields received more nutrient inputs compared to the outfields. Consequently, maize grain yields, partial nutrient balances and soil nutrient stocks were significantly higher in wealthy farms and home fields compared to poor farms and outfields, respectively. These results imply that different soil management strategies are required to achieve similar yields on the different field and farm types and avert soil degradation.
