The Experts below are selected from a list of 8793 Experts worldwide ranked by ideXlab platform
Bram Govaerts - One of the best experts on this subject based on the ideXlab platform.
-
16s metagenomics reveals changes in the soil bacterial community driven by soil organic c n fertilizer and tillage Crop Residue Management
Soil & Tillage Research, 2016Co-Authors: Yosef Chavezromero, Luc Dendooven, Bram Govaerts, Nele Verhulst, Yendi E Navarronoya, Silvia C Reynosomartinez, Yohana Sarriaguzman, Marco LunaguidoAbstract:Abstract Conservation agriculture is a sustainable alternative to conventional agriculture. However, little is known about their effect on the environment and on the soil microbial community. It was established as a hypothesis that the bacterial community structure would be defined by the different agronomic practices. The objective of this study was, therefore, to investigate how Crop Residue Management, tillage and fertilizer application affected the bacterial community and those groups involved in the degradation of applied plant Residues, and increase the knowledge to predict the sustainability of a soil under a specific agronomic practice. Samples from an arable soil from the state of Sonora (Mexico), i.e. Hyposodic Vertisol (Calcaric, Chromic) ( IUSS Working Group, 2007 ), cultivated with wheat (Triticum spp.) and maize ( Zea mays L.) in succession on conventionally tilled beds (CTB) with Crop Residue incorporated, permanent beds (PB) with Residue burned or retained, left unfertilized or fertilized (300 kg N ha −1 for wheat and 103 kg N ha −1 for maize) was improved with dried young wheat plants to stimulate microbial growth, while the bacterial community structure and C and N mineralization were monitored in an aerobic incubation of 56 days. The soil organic C was significantly higher in the PB-Residue retained treatments (average 13.1 g kg −1 dry soil) compared with PB-Residue burned (average 9.9 g kg −1 dry soil) or CTB-Residue incorporated (average 10.5 g kg −1 dry soil), while pH and EC were significantly higher in the PB-Residue burned (averages 8.85 and 1.06 dS m −1 ) compared with the fertilized or unfertilized soil in PB-Residue retained (averages 8.65 and 0.78 dS m −1 ) or CTB-Residue incorporated (averages 8.75 and 0.95 dS m −1 ). In the unimproved soil, we found a significant effect of soil organic C, application of N fertilizer (highly significant on Nitrosovibrio ) and tillage-Residue Management (principally in fertilized soil) on the bacterial community structure, but not in the improved soil. Treatment had no significant effect on the decomposition of the applied organic material, and on average 48% and 9.4% of the applied C and N, respectively, were mineralized in 56 days. Improvement of soil with wheat plant material increased mainly the relative abundance of Actinobacteria and Firmicutes and decreased a wide range of bacterial groups. On the bacterial level of genus, tillage-Residue Management was the most important defining factor of the bacterial community inducing differences in the genera involved in the degradation of applied plant material, i.e. Promicromonospora , Bacillus , Agromyces , Streptomyces , Sinorhizobium and Lysobacter , in different treatments. It was found that nitrogen fertilization and tillage-Crop Residue Management defined the soil bacterial community structure in the unimproved soil, but were less determinant in improved soil, and these results supported the hypothesis tested. It was concluded that all the factors tested, i.e. tillage, Crop-Residue Management and fertilizer application, affect the soil bacterial community structure, while the mineralization potential of the soil was preserved. This study contributes to our understanding of how soil use and Management practices define the soil bacterial community structure.
-
Crop Residue Management and soil health a systems analysis
Agricultural Systems, 2015Co-Authors: Mariesoleil Turmel, Frédéric Baudron, Alicia B Speratti, Nele Verhulst, Bram GovaertsAbstract:Abstract Due to the scarcity of alternative organic amendments, the retention of Crop Residue in fields can be considered key in promoting physical, chemical, and biological attributes of soil health in agricultural systems of developing countries. However, due to multiple other uses, small landholders in these countries are faced with trade-offs in managing Crop Residues. This article reviews Crop Residue Management practices, mainly surface retention, incorporation or removal, describing their advantages and limitations in cereal-based agroecosystems in developing countries. The benefits of Residue retention are regionally variable and depend on both agroclimatic and socioeconomic factors. Most studies from developing countries in Asia, Latin America, and Africa show positive effects of retaining Crop Residues on soil quality, soil organic matter and carbon storage, soil moisture retention, enhanced nutrient cycling, and decreased soil loss, among other environmental and soil health benefits. Variation was observed in the effect of surface retention vs. incorporation on various soil properties indicating the importance of taking into account abiotic factors such as climate, soil texture, study duration, sampling methods, and agronomic practices when assessing the impact of these practices. Negative effects of Residue retention on Crop performance attributed to nitrogen immobilization, waterlogging and decreased soil temperature have also been reported in some environments. Residue trade-offs in mixed Crop-livestock systems in developing countries can limit the amount of Residue retained. However, interventions such as intensification, partial retention, improved return of nutrients from manures, and the provision of substitutes to the current functions of livestock (e.g. mechanization, insurance) could reduce these Residue trade-offs in favour of promoting long-term soil health.
-
effects of tillage and Crop Residue Management on maize yields and net returns in the central mexican highlands under drought conditions
Pedosphere, 2014Co-Authors: Jozef Deckers, Nele Verhulst, R Romeroperezgrovas, D De La Rosa, V Hernandez, Miet Maertens, Bram GovaertsAbstract:In the subtropical highlands of Central Mexico, where the main Crop is maize (Zea mays), the conventional practice (CP) involves tillage, monoculture and Residue removal, leading to soil degradation and unsustainable use of natural resources and agricultural inputs. Conservation agriculture (CA) has been proposed as a viable alternative in the region, based on reduction in tillage, retention of adequate levels of Crop Residues and soil surface cover and use of Crop rotation. This study began in 2009 when the highlands of Central Mexico suffered from a prolonged drought during vegetative maize growth in July–August, providing an opportunity for the on-farm comparison of CA with CP under severe drought conditions which 21 climate change models projected to become more frequent. Under dry conditions, CA resulted in higher yields and net returns per hectare as early as the first and second years after adoption by farmers. As an average of 27 plots under farmers’ Management in 2009, the maize yields were 26% higher under CA (6.3 t ha−1) than under CP (5.0 t ha−1). 2010 was close to a normal year in terms of rainfall so yields were higher than in 2009 for both practices; in addition, the yield difference between the practices was reduced to 19% (6.8 t ha−1 for CA vs. 5.7 t ha−1 for CP). When all the 2009 and 2010 observations were analyzed in a modified stability analysis, CA had an overall positive effect of 3 838 Mexican Pesos ha−1 (320 $US ha−1) on net return and 1.3 t ha−1 on yield. After only one to two years of adoption by farmers on their fields, CA had higher yields and net returns under dry conditions that were even drier than those predicted by the analyzed 21 climate change models under a climate change scenario, emission scenario A2.
-
relative impacts of tillage Residue Management and Crop rotation on soil bacterial communities in a semi arid agroecosystem
Soil Biology & Biochemistry, 2013Co-Authors: Yendi E Navarronoya, Bram Govaerts, Nele Verhulst, Selene Gomezacata, Nina Montoyaciriaco, Aketzally Rojasvaldez, Mayra C Suarezarriaga, Cesar Valenzuelaencinas, Norma G Jimenezbueno, Luc DendoovenAbstract:Abstract In this study, the effect of limited tillage versus traditional tillage, Residue retention versus removal and Crop rotation (maize–wheat) versus monoculture (maize) on the bacterial community structure in soils was investigated by means of 454 pyrosequencing of the 16S rRNA gene. Using taxonomic and phylogenetic information it was found that zero tillage most affected the bacterial communities. The relative abundance of Actinobacteria, Betapreoteobacteria and Gammaproteobacteria was affected by tillage and correlated to the total organic carbon (TOC) and clay content in soil. Residue Management had a significant effect on the bacterial community structure when phylogenetic membership and the total enumeration of bacteria were considered. Residue Management affected the relative abundance of Bacteroidetes, Betaproteobacteria, Cyanobacteria and Gemmatimonadetes. When no tillage was applied, Crop Residue Management affected the microbial communities more than when conventional tillage was applied. Wheat–maize rotation or Crop monoculture did not affect the bacterial community structure. No significant differences in richness, diversity and total abundance of bacteria was found between the treatments. This indicated that even though phylotypes changed, the number and diversity of the bacterial communities were similar.
-
Soil water content, maize yield and its stability as affected by tillage and Crop Residue Management in rainfed semi-arid highlands
Plant and Soil, 2011Co-Authors: Nele Verhulst, Jozef Deckers, Victoria Nelissen, Niels Jespers, Heleen Haven, Ken D. Sayre, Dirk Raes, Bram GovaertsAbstract:Rainfed Crop Management systems need to be optimized to provide more resilient options to cope with projected climatic scenarios forecasting a decrease in mean precipitation and more frequent extreme drought periods in Mexico. Soil water content (0–60 cm) was measured during three Crop cycles in maize plots with different agronomic Management practices in a long-term rainfed experiment (established in 1991) in the highlands of Mexico. Maize yields of 1997–2009 were reported. Crop Management practices varied in (1) tillage (conventional [CT] vs. zero tillage [ZT]) and (2) Residue Management (full or partial retention and removal). ZT with Residue retention had higher soil water content than Management practices involving CT and ZT with Residue removal which provided a buffer for drought periods during the growing seasons. In 2009, a cycle with a prolonged drought during vegetative growth, this resulted in yield differences of up to 4.7 Mg ha^−1 between ZT with (partial) Residue retention and the other practices. Averaged over 1997–2009, these practices had a yield advantage of approximately 1.5 Mg ha^−1 over practices involving CT and ZT with Residue removal. ZT with (partial) Residue retention used rainfall more efficiently and resulted in a more resilient agronomic system than practices involving either CT or ZT with Residue removal.
Rui Yin - One of the best experts on this subject based on the ideXlab platform.
-
tillage and Crop Residue Management significantly affects n trace gas emissions during the non rice season of a subtropical rice wheat rotation
Soil Biology & Biochemistry, 2009Co-Authors: Zhisheng Yao, Xunhua Zheng, Baohua Xie, Baoling Mei, Rui Wang, Klaus Butterbachbahl, Jianguo Zhu, Rui YinAbstract:Abstract Field operations of tillage and Residue incorporation could have potentially important influences on N-trace gas fluxes, though poorly quantified. Here we studied the effects of straw incorporation in the preceding rice season and no-tillage prior to wheat sowing on nitric oxide (NO) and nitrous oxide (N 2 O) emissions during the non-rice period of a typical rice-wheat rotation in the Yangtze River Delta. Compared to conventional Management practice (no straw incorporation along with rotary harrowing tillage to 10 cm before wheat sowing), straw incorporation alone decreased cumulative N 2 O emissions over the entire non-rice period by 32% (1.53 vs. 2.24 kg N ha -1 , P −1 ). In contrast, no-tillage alone increased N 2 O emissions by 75% ( P P 2 O emissions but a reduction in NO emissions compared to the conventional Management regime. The direct N 2 O emission factors (EF d s) of applied nitrogen fertilizers during the non-rice season ranged from 0.29% to 1.35% with a coefficient of variation (CV) as large as 68% among the investigated Management regimes. The EF d s for NO ranged from 0.13% to 0.32% with a CV of 50%. Adoption of these new EF d s will allow us to account for Management effects on N-trace gas emissions when calculating emission inventories. Nevertheless, it is noteworthy that the uncertainty remains high, since the effects of soil properties such as texture or pH on Management practices are not yet well defined.
-
tillage and Crop Residue Management significantly affects n trace gas emissions during the non rice season of a subtropical rice wheat rotation
Soil Biology & Biochemistry, 2009Co-Authors: Zhisheng Yao, Xunhua Zheng, Baohua Xie, Baoling Mei, Rui Wang, Klaus Butterbachbahl, Jianguo Zhu, Rui YinAbstract:Abstract Field operations of tillage and Residue incorporation could have potentially important influences on N-trace gas fluxes, though poorly quantified. Here we studied the effects of straw incorporation in the preceding rice season and no-tillage prior to wheat sowing on nitric oxide (NO) and nitrous oxide (N2O) emissions during the non-rice period of a typical rice-wheat rotation in the Yangtze River Delta. Compared to conventional Management practice (no straw incorporation along with rotary harrowing tillage to 10 cm before wheat sowing), straw incorporation alone decreased cumulative N2O emissions over the entire non-rice period by 32% (1.53 vs. 2.24 kg N ha-1, P
Luc Dendooven - One of the best experts on this subject based on the ideXlab platform.
-
16s metagenomics reveals changes in the soil bacterial community driven by soil organic c n fertilizer and tillage Crop Residue Management
Soil & Tillage Research, 2016Co-Authors: Yosef Chavezromero, Luc Dendooven, Bram Govaerts, Nele Verhulst, Yendi E Navarronoya, Silvia C Reynosomartinez, Yohana Sarriaguzman, Marco LunaguidoAbstract:Abstract Conservation agriculture is a sustainable alternative to conventional agriculture. However, little is known about their effect on the environment and on the soil microbial community. It was established as a hypothesis that the bacterial community structure would be defined by the different agronomic practices. The objective of this study was, therefore, to investigate how Crop Residue Management, tillage and fertilizer application affected the bacterial community and those groups involved in the degradation of applied plant Residues, and increase the knowledge to predict the sustainability of a soil under a specific agronomic practice. Samples from an arable soil from the state of Sonora (Mexico), i.e. Hyposodic Vertisol (Calcaric, Chromic) ( IUSS Working Group, 2007 ), cultivated with wheat (Triticum spp.) and maize ( Zea mays L.) in succession on conventionally tilled beds (CTB) with Crop Residue incorporated, permanent beds (PB) with Residue burned or retained, left unfertilized or fertilized (300 kg N ha −1 for wheat and 103 kg N ha −1 for maize) was improved with dried young wheat plants to stimulate microbial growth, while the bacterial community structure and C and N mineralization were monitored in an aerobic incubation of 56 days. The soil organic C was significantly higher in the PB-Residue retained treatments (average 13.1 g kg −1 dry soil) compared with PB-Residue burned (average 9.9 g kg −1 dry soil) or CTB-Residue incorporated (average 10.5 g kg −1 dry soil), while pH and EC were significantly higher in the PB-Residue burned (averages 8.85 and 1.06 dS m −1 ) compared with the fertilized or unfertilized soil in PB-Residue retained (averages 8.65 and 0.78 dS m −1 ) or CTB-Residue incorporated (averages 8.75 and 0.95 dS m −1 ). In the unimproved soil, we found a significant effect of soil organic C, application of N fertilizer (highly significant on Nitrosovibrio ) and tillage-Residue Management (principally in fertilized soil) on the bacterial community structure, but not in the improved soil. Treatment had no significant effect on the decomposition of the applied organic material, and on average 48% and 9.4% of the applied C and N, respectively, were mineralized in 56 days. Improvement of soil with wheat plant material increased mainly the relative abundance of Actinobacteria and Firmicutes and decreased a wide range of bacterial groups. On the bacterial level of genus, tillage-Residue Management was the most important defining factor of the bacterial community inducing differences in the genera involved in the degradation of applied plant material, i.e. Promicromonospora , Bacillus , Agromyces , Streptomyces , Sinorhizobium and Lysobacter , in different treatments. It was found that nitrogen fertilization and tillage-Crop Residue Management defined the soil bacterial community structure in the unimproved soil, but were less determinant in improved soil, and these results supported the hypothesis tested. It was concluded that all the factors tested, i.e. tillage, Crop-Residue Management and fertilizer application, affect the soil bacterial community structure, while the mineralization potential of the soil was preserved. This study contributes to our understanding of how soil use and Management practices define the soil bacterial community structure.
-
relative impacts of tillage Residue Management and Crop rotation on soil bacterial communities in a semi arid agroecosystem
Soil Biology & Biochemistry, 2013Co-Authors: Yendi E Navarronoya, Bram Govaerts, Nele Verhulst, Selene Gomezacata, Nina Montoyaciriaco, Aketzally Rojasvaldez, Mayra C Suarezarriaga, Cesar Valenzuelaencinas, Norma G Jimenezbueno, Luc DendoovenAbstract:Abstract In this study, the effect of limited tillage versus traditional tillage, Residue retention versus removal and Crop rotation (maize–wheat) versus monoculture (maize) on the bacterial community structure in soils was investigated by means of 454 pyrosequencing of the 16S rRNA gene. Using taxonomic and phylogenetic information it was found that zero tillage most affected the bacterial communities. The relative abundance of Actinobacteria, Betapreoteobacteria and Gammaproteobacteria was affected by tillage and correlated to the total organic carbon (TOC) and clay content in soil. Residue Management had a significant effect on the bacterial community structure when phylogenetic membership and the total enumeration of bacteria were considered. Residue Management affected the relative abundance of Bacteroidetes, Betaproteobacteria, Cyanobacteria and Gemmatimonadetes. When no tillage was applied, Crop Residue Management affected the microbial communities more than when conventional tillage was applied. Wheat–maize rotation or Crop monoculture did not affect the bacterial community structure. No significant differences in richness, diversity and total abundance of bacteria was found between the treatments. This indicated that even though phylotypes changed, the number and diversity of the bacterial communities were similar.
-
conventionally tilled and permanent raised beds with different Crop Residue Management effects on soil c and n dynamics
Plant and Soil, 2006Co-Authors: Bram Govaerts, J M Ceballosramirez, Marco Lunaguido, Kenneth D. Sayre, Agustin Limonortega, Jozef Deckers, Luc DendoovenAbstract:Conservation tillage in its version of permanent bed planting under zero-tillage with Crop Residue retention has been proposed as an alternative wheat production system for northwest Mexico. However, little is known about the dynamics of C and N in soils under wheat/maize on permanent beds (PB) where straw was burned, removed, partly removed or retained, as opposed to conventionally tilled beds (CTB) where straw was incorporated. We investigated the dynamics of soil C and N and normalized difference vegetative index (NDVI) Crop values in zero-tilled PB and CTB after 26 successive maize and wheat Crops. Organic C and total N were respectively, 1.15 and 1.17 times greater in PB with straw partly removed and with straw retained on the surface, than in CTB with straw incorporated. Organic C and total N were 1.10 times greater in soils with 300 kg N ha−1 added than in unfertilized soil. Cumulative production of CO2 was lower under CTB with straw incorporated than under PB treatments, and CO2 production increased with increments in inorganic fertilizer. The N-mineralization rate was 1.18 times greater than in unamended soils when 150 kg inorganic N ha−1 was applied, and 1.48 times greater when 300 kg inorganic N ha−1 was added. The N-mineralization rate was significantly (1.66 times) greater in PB where the straw was burned or retained on the surface than in CTB where the straw was incorporated, but significantly (1.25 times) lower than in PB with straw partly removed. The NDVI values reached a maximum 56 days after planting and decreased thereafter. The NDVI for unfertilized soil were similar for CTB with straw incorporated, PB with straw partly removed, and PB with straw retained on the surface, but significantly lower for PB with straw burned and PB with straw removed. In soils to which 150 or 300 kg N ha−1 was added, NDVI was significantly lower for PB with straw burned than for other treatments. Among other things, this suggests the utility of rotating maize or wheat with Crops whose Residues have lower C–N ratios, thus avoiding immobilization of large amounts of N for extended periods. PB with Residue burning, however, is an unsustainable practice leading to low Crop performance and soil and environmental degradation.
Zhisheng Yao - One of the best experts on this subject based on the ideXlab platform.
-
tillage and Crop Residue Management significantly affects n trace gas emissions during the non rice season of a subtropical rice wheat rotation
Soil Biology & Biochemistry, 2009Co-Authors: Zhisheng Yao, Xunhua Zheng, Baohua Xie, Baoling Mei, Rui Wang, Klaus Butterbachbahl, Jianguo Zhu, Rui YinAbstract:Abstract Field operations of tillage and Residue incorporation could have potentially important influences on N-trace gas fluxes, though poorly quantified. Here we studied the effects of straw incorporation in the preceding rice season and no-tillage prior to wheat sowing on nitric oxide (NO) and nitrous oxide (N 2 O) emissions during the non-rice period of a typical rice-wheat rotation in the Yangtze River Delta. Compared to conventional Management practice (no straw incorporation along with rotary harrowing tillage to 10 cm before wheat sowing), straw incorporation alone decreased cumulative N 2 O emissions over the entire non-rice period by 32% (1.53 vs. 2.24 kg N ha -1 , P −1 ). In contrast, no-tillage alone increased N 2 O emissions by 75% ( P P 2 O emissions but a reduction in NO emissions compared to the conventional Management regime. The direct N 2 O emission factors (EF d s) of applied nitrogen fertilizers during the non-rice season ranged from 0.29% to 1.35% with a coefficient of variation (CV) as large as 68% among the investigated Management regimes. The EF d s for NO ranged from 0.13% to 0.32% with a CV of 50%. Adoption of these new EF d s will allow us to account for Management effects on N-trace gas emissions when calculating emission inventories. Nevertheless, it is noteworthy that the uncertainty remains high, since the effects of soil properties such as texture or pH on Management practices are not yet well defined.
-
tillage and Crop Residue Management significantly affects n trace gas emissions during the non rice season of a subtropical rice wheat rotation
Soil Biology & Biochemistry, 2009Co-Authors: Zhisheng Yao, Xunhua Zheng, Baohua Xie, Baoling Mei, Rui Wang, Klaus Butterbachbahl, Jianguo Zhu, Rui YinAbstract:Abstract Field operations of tillage and Residue incorporation could have potentially important influences on N-trace gas fluxes, though poorly quantified. Here we studied the effects of straw incorporation in the preceding rice season and no-tillage prior to wheat sowing on nitric oxide (NO) and nitrous oxide (N2O) emissions during the non-rice period of a typical rice-wheat rotation in the Yangtze River Delta. Compared to conventional Management practice (no straw incorporation along with rotary harrowing tillage to 10 cm before wheat sowing), straw incorporation alone decreased cumulative N2O emissions over the entire non-rice period by 32% (1.53 vs. 2.24 kg N ha-1, P
Nele Verhulst - One of the best experts on this subject based on the ideXlab platform.
-
16s metagenomics reveals changes in the soil bacterial community driven by soil organic c n fertilizer and tillage Crop Residue Management
Soil & Tillage Research, 2016Co-Authors: Yosef Chavezromero, Luc Dendooven, Bram Govaerts, Nele Verhulst, Yendi E Navarronoya, Silvia C Reynosomartinez, Yohana Sarriaguzman, Marco LunaguidoAbstract:Abstract Conservation agriculture is a sustainable alternative to conventional agriculture. However, little is known about their effect on the environment and on the soil microbial community. It was established as a hypothesis that the bacterial community structure would be defined by the different agronomic practices. The objective of this study was, therefore, to investigate how Crop Residue Management, tillage and fertilizer application affected the bacterial community and those groups involved in the degradation of applied plant Residues, and increase the knowledge to predict the sustainability of a soil under a specific agronomic practice. Samples from an arable soil from the state of Sonora (Mexico), i.e. Hyposodic Vertisol (Calcaric, Chromic) ( IUSS Working Group, 2007 ), cultivated with wheat (Triticum spp.) and maize ( Zea mays L.) in succession on conventionally tilled beds (CTB) with Crop Residue incorporated, permanent beds (PB) with Residue burned or retained, left unfertilized or fertilized (300 kg N ha −1 for wheat and 103 kg N ha −1 for maize) was improved with dried young wheat plants to stimulate microbial growth, while the bacterial community structure and C and N mineralization were monitored in an aerobic incubation of 56 days. The soil organic C was significantly higher in the PB-Residue retained treatments (average 13.1 g kg −1 dry soil) compared with PB-Residue burned (average 9.9 g kg −1 dry soil) or CTB-Residue incorporated (average 10.5 g kg −1 dry soil), while pH and EC were significantly higher in the PB-Residue burned (averages 8.85 and 1.06 dS m −1 ) compared with the fertilized or unfertilized soil in PB-Residue retained (averages 8.65 and 0.78 dS m −1 ) or CTB-Residue incorporated (averages 8.75 and 0.95 dS m −1 ). In the unimproved soil, we found a significant effect of soil organic C, application of N fertilizer (highly significant on Nitrosovibrio ) and tillage-Residue Management (principally in fertilized soil) on the bacterial community structure, but not in the improved soil. Treatment had no significant effect on the decomposition of the applied organic material, and on average 48% and 9.4% of the applied C and N, respectively, were mineralized in 56 days. Improvement of soil with wheat plant material increased mainly the relative abundance of Actinobacteria and Firmicutes and decreased a wide range of bacterial groups. On the bacterial level of genus, tillage-Residue Management was the most important defining factor of the bacterial community inducing differences in the genera involved in the degradation of applied plant material, i.e. Promicromonospora , Bacillus , Agromyces , Streptomyces , Sinorhizobium and Lysobacter , in different treatments. It was found that nitrogen fertilization and tillage-Crop Residue Management defined the soil bacterial community structure in the unimproved soil, but were less determinant in improved soil, and these results supported the hypothesis tested. It was concluded that all the factors tested, i.e. tillage, Crop-Residue Management and fertilizer application, affect the soil bacterial community structure, while the mineralization potential of the soil was preserved. This study contributes to our understanding of how soil use and Management practices define the soil bacterial community structure.
-
Crop Residue Management and soil health a systems analysis
Agricultural Systems, 2015Co-Authors: Mariesoleil Turmel, Frédéric Baudron, Alicia B Speratti, Nele Verhulst, Bram GovaertsAbstract:Abstract Due to the scarcity of alternative organic amendments, the retention of Crop Residue in fields can be considered key in promoting physical, chemical, and biological attributes of soil health in agricultural systems of developing countries. However, due to multiple other uses, small landholders in these countries are faced with trade-offs in managing Crop Residues. This article reviews Crop Residue Management practices, mainly surface retention, incorporation or removal, describing their advantages and limitations in cereal-based agroecosystems in developing countries. The benefits of Residue retention are regionally variable and depend on both agroclimatic and socioeconomic factors. Most studies from developing countries in Asia, Latin America, and Africa show positive effects of retaining Crop Residues on soil quality, soil organic matter and carbon storage, soil moisture retention, enhanced nutrient cycling, and decreased soil loss, among other environmental and soil health benefits. Variation was observed in the effect of surface retention vs. incorporation on various soil properties indicating the importance of taking into account abiotic factors such as climate, soil texture, study duration, sampling methods, and agronomic practices when assessing the impact of these practices. Negative effects of Residue retention on Crop performance attributed to nitrogen immobilization, waterlogging and decreased soil temperature have also been reported in some environments. Residue trade-offs in mixed Crop-livestock systems in developing countries can limit the amount of Residue retained. However, interventions such as intensification, partial retention, improved return of nutrients from manures, and the provision of substitutes to the current functions of livestock (e.g. mechanization, insurance) could reduce these Residue trade-offs in favour of promoting long-term soil health.
-
effects of tillage and Crop Residue Management on maize yields and net returns in the central mexican highlands under drought conditions
Pedosphere, 2014Co-Authors: Jozef Deckers, Nele Verhulst, R Romeroperezgrovas, D De La Rosa, V Hernandez, Miet Maertens, Bram GovaertsAbstract:In the subtropical highlands of Central Mexico, where the main Crop is maize (Zea mays), the conventional practice (CP) involves tillage, monoculture and Residue removal, leading to soil degradation and unsustainable use of natural resources and agricultural inputs. Conservation agriculture (CA) has been proposed as a viable alternative in the region, based on reduction in tillage, retention of adequate levels of Crop Residues and soil surface cover and use of Crop rotation. This study began in 2009 when the highlands of Central Mexico suffered from a prolonged drought during vegetative maize growth in July–August, providing an opportunity for the on-farm comparison of CA with CP under severe drought conditions which 21 climate change models projected to become more frequent. Under dry conditions, CA resulted in higher yields and net returns per hectare as early as the first and second years after adoption by farmers. As an average of 27 plots under farmers’ Management in 2009, the maize yields were 26% higher under CA (6.3 t ha−1) than under CP (5.0 t ha−1). 2010 was close to a normal year in terms of rainfall so yields were higher than in 2009 for both practices; in addition, the yield difference between the practices was reduced to 19% (6.8 t ha−1 for CA vs. 5.7 t ha−1 for CP). When all the 2009 and 2010 observations were analyzed in a modified stability analysis, CA had an overall positive effect of 3 838 Mexican Pesos ha−1 (320 $US ha−1) on net return and 1.3 t ha−1 on yield. After only one to two years of adoption by farmers on their fields, CA had higher yields and net returns under dry conditions that were even drier than those predicted by the analyzed 21 climate change models under a climate change scenario, emission scenario A2.
-
relative impacts of tillage Residue Management and Crop rotation on soil bacterial communities in a semi arid agroecosystem
Soil Biology & Biochemistry, 2013Co-Authors: Yendi E Navarronoya, Bram Govaerts, Nele Verhulst, Selene Gomezacata, Nina Montoyaciriaco, Aketzally Rojasvaldez, Mayra C Suarezarriaga, Cesar Valenzuelaencinas, Norma G Jimenezbueno, Luc DendoovenAbstract:Abstract In this study, the effect of limited tillage versus traditional tillage, Residue retention versus removal and Crop rotation (maize–wheat) versus monoculture (maize) on the bacterial community structure in soils was investigated by means of 454 pyrosequencing of the 16S rRNA gene. Using taxonomic and phylogenetic information it was found that zero tillage most affected the bacterial communities. The relative abundance of Actinobacteria, Betapreoteobacteria and Gammaproteobacteria was affected by tillage and correlated to the total organic carbon (TOC) and clay content in soil. Residue Management had a significant effect on the bacterial community structure when phylogenetic membership and the total enumeration of bacteria were considered. Residue Management affected the relative abundance of Bacteroidetes, Betaproteobacteria, Cyanobacteria and Gemmatimonadetes. When no tillage was applied, Crop Residue Management affected the microbial communities more than when conventional tillage was applied. Wheat–maize rotation or Crop monoculture did not affect the bacterial community structure. No significant differences in richness, diversity and total abundance of bacteria was found between the treatments. This indicated that even though phylotypes changed, the number and diversity of the bacterial communities were similar.
-
Soil water content, maize yield and its stability as affected by tillage and Crop Residue Management in rainfed semi-arid highlands
Plant and Soil, 2011Co-Authors: Nele Verhulst, Jozef Deckers, Victoria Nelissen, Niels Jespers, Heleen Haven, Ken D. Sayre, Dirk Raes, Bram GovaertsAbstract:Rainfed Crop Management systems need to be optimized to provide more resilient options to cope with projected climatic scenarios forecasting a decrease in mean precipitation and more frequent extreme drought periods in Mexico. Soil water content (0–60 cm) was measured during three Crop cycles in maize plots with different agronomic Management practices in a long-term rainfed experiment (established in 1991) in the highlands of Mexico. Maize yields of 1997–2009 were reported. Crop Management practices varied in (1) tillage (conventional [CT] vs. zero tillage [ZT]) and (2) Residue Management (full or partial retention and removal). ZT with Residue retention had higher soil water content than Management practices involving CT and ZT with Residue removal which provided a buffer for drought periods during the growing seasons. In 2009, a cycle with a prolonged drought during vegetative growth, this resulted in yield differences of up to 4.7 Mg ha^−1 between ZT with (partial) Residue retention and the other practices. Averaged over 1997–2009, these practices had a yield advantage of approximately 1.5 Mg ha^−1 over practices involving CT and ZT with Residue removal. ZT with (partial) Residue retention used rainfall more efficiently and resulted in a more resilient agronomic system than practices involving either CT or ZT with Residue removal.