The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Riziki S. Shemdoe - One of the best experts on this subject based on the ideXlab platform.
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Weed species diversity on arable land of the dryland areas of central Tanzania: impacts of Continuous Application of traditional tillage practices
GeoJournal, 2008Co-Authors: Riziki S. Shemdoe, Frank M. Mbago, Idris S. Kikula, Patrick Van DammeAbstract:This paper presents findings from a study that assessed influence of Continuous Application of a particular traditional tillage practice on weed species richness, diversity and composition and identifies weed species with positive benefits to the communities in semi-arid areas of Mpwapwa district, central Tanzania. In this area farmers apply three different traditional tillage practices which are no-till (NT), shallow tillage (ST) and Ridging System (RT). A total of 36 farm fields were surveyed in 2006/2007 cropping season where 63 weed species from 26 families were identified. Analysis of variance indicated significant differences between practices (p < 0.05), with NT practice having highest weed species richness and diversity. Among the five more prevalent weed species appearing, Bidens lineariloba was observed to exist in all the three practices. Community representatives during focus group discussions indicated 9 weed species out of 63 identified to have beneficial uses. These species are Cleome hirta, Amaranthus graecizans, Bidens lineoriloba, Bidens pilosa, Dactyloctenium aegyptium, Launaea cornuta, Heteropogon contortus, Tragus berteronianus and Trichodesma zeylanicum. Their main uses include leaf-vegetable, medicines, fodder and materials for thatching. From this study NT has highest weed species richness and diversity which therefore suggests that much more time is needed for weeding in this practice compared to other practice which was the farmers’ concern. It was also noted that although weed species have negative effects in crop production and production costs, they still play a vital role in food security and for the health of different people in marginal areas as well as for the complete ecosystem including micro and macrofauna.
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Weed species diversity on arable land of the dryland areas of central Tanzania: impacts of Continuous Application of traditional tillage practices
GeoJournal, 2008Co-Authors: Riziki S. Shemdoe, Frank M. Mbago, Idris S. Kikula, Patrick L. DammeAbstract:This paper presents findings from a study that assessed influence of Continuous Application of a particular traditional tillage practice on weed species richness, diversity and composition and identifies weed species with positive benefits to the communities in semi-arid areas of Mpwapwa district, central Tanzania. In this area farmers apply three different traditional tillage practices which are no-till (NT), shallow tillage (ST) and Ridging System (RT). A total of 36 farm fields were surveyed in 2006/2007 cropping season where 63 weed species from 26 families were identified. Analysis of variance indicated significant differences between practices ( p
I. Watanabe - One of the best experts on this subject based on the ideXlab platform.
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Green manure production of Azolla microphylla and Sesbania rostrata and their long-term effects on rice yields and soil fertility
Biology and Fertility of Soils, 1993Co-Authors: W. Ventura, I. WatanabeAbstract:Azolla spp. and Sesbania spp. can be used as green manure crops for wetland rice. A long-term experiment was started in 1985 to determine the effects of organic and urea fertilizers on wetland rice yields and soil fertility. Results of 10 rice croppings are reported. Azolla sp. was grown for 1 month and then incorporated before transplanting the rice and 3–4 weeks after transplanting the rice. Sesbania rostrata was grown for 7–9 weeks and incorporated only before transplanting the rice. Sesbania sp. grew more poorly before dry season rice than before wet season rice. Aeschynomene afraspera , which was used in one dry season rice trial, produced a larger biomass than the Sesbania sp. The quantity of N produced by the Azolla sp. ranged from 70 to 110 kg N ha^-1. The Sesbania sp. produced 55–90 kg N ha^-1 in 46–62 days. Rice grain yield increases in response to the green manure were 1.8–3.9 t ha^-1, similar to or higher than that obtained in response to the Application of 60 kg N ha^-1 as urea. Grain production per unit weight of absorbed N was lower in the green manure treatments than in the urea treatment. Without N fertilizer, N uptake by rice decreased as the number of rice crops increased. For similar N recoveries, Sesbania sp. required a lower N concentration than the Azolla sp. did. Continuous Application of the green manure increased the organic N content in soil on a dry weight basis, but not on a area basis, because the Application of green manure decreased soil bulk density. Residual effects in the grain yield and N uptake of rice after nine rice crops were found with a Continuous Application of green manure but not urea.
De-chun Su - One of the best experts on this subject based on the ideXlab platform.
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Accumulation and bioavailability of heavy metals in an acid soil and their uptake by paddy rice under Continuous Application of chicken and swine manure.
Journal of Hazardous Materials, 2019Co-Authors: Qingqing Huang, De-chun Su, Qi Wang, Yao Yu, Yuhui Qiao, Huafen LiAbstract:Abstract Heavy metal contamination of agricultural soils is a global concern, as it can cause the accumulation of heavy metals in food. In this study, a field experiment was carried out to investigate the effect of the Continuous Application of chicken or swine manure on the Pb, Cd, Cr and As bioavailability, fractionation, and accumulation in soil and uptake by rice plants. Results showed that chicken or swine manure significantly reduced the Cd and Pb contents in rice grain by 7.8–79.3% and 7.2–59.4%, respectively, with increasing Application rates and number of years; the exchangeable Cd and Pb fractions, and the diethylenetriaminepentaacetic acid (DTPA)-extractable Cd and Pb in the soil were also decreased. Furthermore, the Application of chicken or swine manure substantially increased the DTPA-extractable As and exchangeable As fractions in the soil but had limited effect on As accumulation in rice grain. No significant differences in the bioavailability in soil nor accumulation in the rice grain were found for Cr between the treatments. Therefore, livestock manure can be used as soil amendments to decrease Cd and Pb accumulation in rice grains, nevertheless, the potential risk of metal accumulation in soils caused by livestock manure Application should be considered.
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Distribution of Phosphorus in Soil Profiles after Continuous Application of Different Fertilizers
Huan jing ke xue= Huanjing kexue, 2017Co-Authors: Tian Zhang, Hao Xu, Shu-hua Ru, De-chun SuAbstract:: This study clarifies the distribution and migration characteristics of phosphorus in the soil profile and discusses the phosphorus load of farmland after Continuous Application of different organic fertilizers. The distribution and migration characteristics of phosphorus in soil profiles were studied through a field experiment lasting four consecutive years. The results showed that total phosphorus and Olsen-P are mainly accumulated in the soil surface, and their contents decrease with the deepening of soil depth after the Continuous Application of different fertilizers. With a four-year Application of higher levels of organic fertilizer, the total phosphorus was found to migrate into the 15-30 cm soil layer. Olsen-P was found to migrate into the 60-90 cm soil layer under higher levels of pig manure. The ratio of available phosphorus to total phosphorus in the soil surface increased, and there were significant differences after the Application of different amounts of organic fertilizers. The amount of Olsen-P as a proportion of total phosphorus in the soil profile decreased as pig manure treatment > chicken manure treatment > sludge treatment > phosphate fertilizer treatment. After the Application of chicken manure, pig manure, sludge, and phosphate fertilizer, the value of Olsen-P in the soil surface increased with an increase in phosphorus input and then remained stable. When applying the same phosphorus onto the soil, the contribution of different organic fertilizers to Olsen-P in the surface soil was quite different. The bioavailability and mobility of phosphorus from pig manure was significantly higher than that of chicken manure, sludge, and phosphate fertilizer.
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Effects of Continuous Application of Sewage Sludge Compost on Heavy Metals Accumulation and Mobility Characteristics in Soil Profile and on Heavy Metals Uptake of Wheat
Huan jing ke xue= Huanjing kexue, 2017Co-Authors: He-ping Shang, Shu-hua Ru, De-chun SuAbstract:: The use of sewage sludge compost(SSC)as fertilizer may cause increased leaching due to its high content of heavy metals and thus pose a threat to groundwater quality. The effect of SSC Application on heavy metals leaching in calcareous soils has been studied in field trials, which provides basis for determining heavy metals environmental capacity and preventing metal pollution in farmland soil scientifically. The results indicated that the contents of Cu, Zn elevated obviously with the increase of the age and the dosage of SSC utilization in the topsoil(0-15 cm) under 4-year Continuous Application of SSC. Under higher levels of the compost treatment, the heavy metals Cu and Zn were found to migrate into the 15-30 cm soil and 60-90 cm soil under the experimental condition. Nevertheless, the majority of Cu and Zn from SSC accumulated in topsoil and the highest accumulation rates could reach 75.3% for Cu and 85.9% for Zn. The contents of Cd, Pb increased significantly in topsoil after 4-year Continuous Application of SSC, and their increases could reach 57.2%-165.2% for Cd and 13%-34% for Pb compared with CK. At 60-90 cm soil, the contents of Cr, As and Pb were also significantly higher than those in CK treatment. Application of SSC not only caused accumulation of some heavy metals in topsoil but also leached heavy metals located in the subsurface soil down in this experiment. Continuous utilization of SSC increased Zn concentration of wheat grain, and the increase could reach 13.3%-47.9%. For the concentrations of Cr and Pb in wheat grain, the values exceeded the national food and healthy standards value (GB 2762-2012) in part of compost treatments. The cumulative ratio of heavy metals carried out by wheat were all below 10% after 4-year experiment, wheat grain carried much more Cu, Zn out than wheat straw, but it was opposite for Cr, As, Cd, Pb. The cumulative ratio of heavy metals carried by wheat decreased with the increasing level of SSC utilization. The amounts of heavy metals migrated to deeper soil should be considered when determining the environmental capacity of heavy metals in farmland soil.
Patrick L. Damme - One of the best experts on this subject based on the ideXlab platform.
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Weed species diversity on arable land of the dryland areas of central Tanzania: impacts of Continuous Application of traditional tillage practices
GeoJournal, 2008Co-Authors: Riziki S. Shemdoe, Frank M. Mbago, Idris S. Kikula, Patrick L. DammeAbstract:This paper presents findings from a study that assessed influence of Continuous Application of a particular traditional tillage practice on weed species richness, diversity and composition and identifies weed species with positive benefits to the communities in semi-arid areas of Mpwapwa district, central Tanzania. In this area farmers apply three different traditional tillage practices which are no-till (NT), shallow tillage (ST) and Ridging System (RT). A total of 36 farm fields were surveyed in 2006/2007 cropping season where 63 weed species from 26 families were identified. Analysis of variance indicated significant differences between practices ( p
Patrick Van Damme - One of the best experts on this subject based on the ideXlab platform.
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Weed species diversity on arable land of the dryland areas of central Tanzania: impacts of Continuous Application of traditional tillage practices
GeoJournal, 2008Co-Authors: Riziki S. Shemdoe, Frank M. Mbago, Idris S. Kikula, Patrick Van DammeAbstract:This paper presents findings from a study that assessed influence of Continuous Application of a particular traditional tillage practice on weed species richness, diversity and composition and identifies weed species with positive benefits to the communities in semi-arid areas of Mpwapwa district, central Tanzania. In this area farmers apply three different traditional tillage practices which are no-till (NT), shallow tillage (ST) and Ridging System (RT). A total of 36 farm fields were surveyed in 2006/2007 cropping season where 63 weed species from 26 families were identified. Analysis of variance indicated significant differences between practices (p < 0.05), with NT practice having highest weed species richness and diversity. Among the five more prevalent weed species appearing, Bidens lineariloba was observed to exist in all the three practices. Community representatives during focus group discussions indicated 9 weed species out of 63 identified to have beneficial uses. These species are Cleome hirta, Amaranthus graecizans, Bidens lineoriloba, Bidens pilosa, Dactyloctenium aegyptium, Launaea cornuta, Heteropogon contortus, Tragus berteronianus and Trichodesma zeylanicum. Their main uses include leaf-vegetable, medicines, fodder and materials for thatching. From this study NT has highest weed species richness and diversity which therefore suggests that much more time is needed for weeding in this practice compared to other practice which was the farmers’ concern. It was also noted that although weed species have negative effects in crop production and production costs, they still play a vital role in food security and for the health of different people in marginal areas as well as for the complete ecosystem including micro and macrofauna.