Pub Date : 2022-09-26DOI: 10.1017/S0014479722000321
J. L. C. Baptistella, Ana Paula Bettoni Teles, J. L. Favarin, P. Pavinato, P. Mazzafera
Summary Phosphorus (P) is a limiting resource for agricultural production in the tropics. Urochloa spp. is commonly used as a cover crop and has mechanisms to mobilize partially the nonavailable P forms from the soil. The use of Urochloa intercropped with Arabica coffee (Coffea arabica L.) is increasing in Brazil, but P cycling has been overlooked in this system. Here, we proposed two experiments to test the hypothesis that Urochloa decumbens could mobilize and absorb P from deep soil layers and increase overall P cycling of the intercrop system. We measured U. decumbens root and shoot dry mass (SDM), root morphology and activity, nutrient uptake, soil nutrient availability, and soil P fractionation in both experiments. To better understand P cycling by Urochloa alone, in the first experiment, U. decumbens was cultivated in rhizotrons where adequate P was supplied in distinct soil layers – 0.0 to 0.3 m, 0.3 to 0.8 m, 0.8 to 1.3 m, and 1.3 to 2 m. Root dry mass (RDM) and morphology were not affected by P availability. Moreover, total biomass production (root plus shoot) and P uptake were higher when P was available in the superficial top soil layer compared to P availability in more than one layer or only in the bottom layer. Nevertheless, U. decumbens was able to reach and acquire P from depth. Correlation analysis showed that P cycling was strongly dependent on SDM, labile, and moderately labile fractions of soil P and was not significantly correlated with RDM. The second experiment aimed at verifying P uptake and mobilization from different soil depths in field conditions. P was supplied in different depths of the soil profile – 0.3 m, 0.6 m, and 0.9 m – in the field with preestablished U. decumbens intercropped with Arabica coffee plants. Shoot P content was higher at the first sample date when P was supplied at 0.3 m, compared to 0.6 m, 0.9 m, and control with no P. Soil P fractionation showed that there was no P mobilization of less labile forms by U. decumbens during the evaluated time. Our results showed that P fertilization in the top layer rather than suppling P trough the soil profile can maximize U. decumbens growth. Also, Urochloa P accumulation was enough to support coffee demand even in high yields and can be an alternative to increase P use efficiency in coffee production systems, being an effective recycler of P.
{"title":"Phosphorus cycling by Urochloa decumbens intercropped with coffee","authors":"J. L. C. Baptistella, Ana Paula Bettoni Teles, J. L. Favarin, P. Pavinato, P. Mazzafera","doi":"10.1017/S0014479722000321","DOIUrl":"https://doi.org/10.1017/S0014479722000321","url":null,"abstract":"Summary Phosphorus (P) is a limiting resource for agricultural production in the tropics. Urochloa spp. is commonly used as a cover crop and has mechanisms to mobilize partially the nonavailable P forms from the soil. The use of Urochloa intercropped with Arabica coffee (Coffea arabica L.) is increasing in Brazil, but P cycling has been overlooked in this system. Here, we proposed two experiments to test the hypothesis that Urochloa decumbens could mobilize and absorb P from deep soil layers and increase overall P cycling of the intercrop system. We measured U. decumbens root and shoot dry mass (SDM), root morphology and activity, nutrient uptake, soil nutrient availability, and soil P fractionation in both experiments. To better understand P cycling by Urochloa alone, in the first experiment, U. decumbens was cultivated in rhizotrons where adequate P was supplied in distinct soil layers – 0.0 to 0.3 m, 0.3 to 0.8 m, 0.8 to 1.3 m, and 1.3 to 2 m. Root dry mass (RDM) and morphology were not affected by P availability. Moreover, total biomass production (root plus shoot) and P uptake were higher when P was available in the superficial top soil layer compared to P availability in more than one layer or only in the bottom layer. Nevertheless, U. decumbens was able to reach and acquire P from depth. Correlation analysis showed that P cycling was strongly dependent on SDM, labile, and moderately labile fractions of soil P and was not significantly correlated with RDM. The second experiment aimed at verifying P uptake and mobilization from different soil depths in field conditions. P was supplied in different depths of the soil profile – 0.3 m, 0.6 m, and 0.9 m – in the field with preestablished U. decumbens intercropped with Arabica coffee plants. Shoot P content was higher at the first sample date when P was supplied at 0.3 m, compared to 0.6 m, 0.9 m, and control with no P. Soil P fractionation showed that there was no P mobilization of less labile forms by U. decumbens during the evaluated time. Our results showed that P fertilization in the top layer rather than suppling P trough the soil profile can maximize U. decumbens growth. Also, Urochloa P accumulation was enough to support coffee demand even in high yields and can be an alternative to increase P use efficiency in coffee production systems, being an effective recycler of P.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49099186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-05DOI: 10.1017/S001447972200028X
Haftamu Gebretsadik Gebrehiwot, J. Aune, O. Eklo, T. Torp, L. Brandsæter
Summary Field experiments were conducted in 2015 and 2016 to study the effect of tillage frequency, seed rate, and glyphosate on teff and weeds. The experiments were arranged in a split plot design with three replications consisting of tillage frequency (conventional, minimum, and zero tillage) as the main plot and the combination of seed rate (5, 15, and 25 kg ha−1) and glyphosate (with and without) as subplots. Results showed that zero tillage reduced teff biomass yield by 15% compared to minimum tillage and by 26% compared to conventional tillage. Zero tillage and minimum tillage also diminished grain yield by 21% and 13%, respectively, compared to conventional tillage. Lowering the seed rate to 5 kg ha−1 reduced biomass yield by 22% and 26% compared to 15 and 25 kg ha−1, respectively. It also reduced the grain yield by around 21% compared to 15 and 25 kg ha−1 seed rates. Conventional tillage significantly diminished weed density, dry weight, and cover by 19%, 29%, and 33%, respectively, compared to zero tillage. The highest seed rate significantly reduced total weed density, dry weight, and cover by 18%, 19%, and 15%, respectively, compared to the lowest seed rate. Glyphosate did not affect weed density but reduced weed dry weight by 14% and cover by 15%. Generally, sowing teff using minimum tillage combined with glyphosate application and seed rate of 15 kg ha−1 enhanced its productivity and minimized weed effects.
总结2015年和2016年进行了田间试验，研究了耕作频率、种子率和草甘膦对聚四氟乙烯和杂草的影响。试验采用分块设计，三次重复，以耕作频率（常规、最低和免耕）为主要地块，种子率（5、15和25 kg ha−1）和草甘膦（有和无）组合为次要地块。结果表明，免耕使聚四氟乙烯生物量产量比少耕减少15%，比常规耕作减少26%。与传统耕作相比，免耕和少耕也分别使粮食产量下降21%和13%。与15和25 kg ha−1相比，将种子率降低到5 kg ha−2可使生物量产量分别降低22%和26%。与15和25 kg ha−1的播种率相比，它还使粮食产量降低了约21%。与免耕相比，常规耕作显著降低了杂草密度、干重和覆盖率，分别降低了19%、29%和33%。与最低种子率相比，最高种子率显著降低了总杂草密度、干重和覆盖率，分别降低了18%、19%和15%。草甘膦不影响杂草密度，但使杂草干重减少14%，覆盖率减少15%。一般来说，采用最少耕作结合草甘膦施用和15 kg ha−1的播种率播种聚四氟乙烯，可以提高生产力，并将杂草影响降至最低。
{"title":"Effect of tillage frequency, seed rate, and glyphosate application on teff and weeds in Tigray, Ethiopia","authors":"Haftamu Gebretsadik Gebrehiwot, J. Aune, O. Eklo, T. Torp, L. Brandsæter","doi":"10.1017/S001447972200028X","DOIUrl":"https://doi.org/10.1017/S001447972200028X","url":null,"abstract":"Summary Field experiments were conducted in 2015 and 2016 to study the effect of tillage frequency, seed rate, and glyphosate on teff and weeds. The experiments were arranged in a split plot design with three replications consisting of tillage frequency (conventional, minimum, and zero tillage) as the main plot and the combination of seed rate (5, 15, and 25 kg ha−1) and glyphosate (with and without) as subplots. Results showed that zero tillage reduced teff biomass yield by 15% compared to minimum tillage and by 26% compared to conventional tillage. Zero tillage and minimum tillage also diminished grain yield by 21% and 13%, respectively, compared to conventional tillage. Lowering the seed rate to 5 kg ha−1 reduced biomass yield by 22% and 26% compared to 15 and 25 kg ha−1, respectively. It also reduced the grain yield by around 21% compared to 15 and 25 kg ha−1 seed rates. Conventional tillage significantly diminished weed density, dry weight, and cover by 19%, 29%, and 33%, respectively, compared to zero tillage. The highest seed rate significantly reduced total weed density, dry weight, and cover by 18%, 19%, and 15%, respectively, compared to the lowest seed rate. Glyphosate did not affect weed density but reduced weed dry weight by 14% and cover by 15%. Generally, sowing teff using minimum tillage combined with glyphosate application and seed rate of 15 kg ha−1 enhanced its productivity and minimized weed effects.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49485787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-17DOI: 10.1017/S0014479722000229
O. T. Kölln, B. N. Boschiero, H. Franco, Marina Camara Martins Soldi, G. Sanches, S. Castro, P. Trivelin
Summary Ammonium has been reported as a ‘preferred’ nitrogen (N) source for sugarcane (Saccharum spp.), which can improve N use efficiency (NUE) in this crop. We aimed to evaluate the preferential uptake of ammonium and nitrate in sugarcane genotypes contrasting with NUE under controlled conditions. Four sugarcane genotypes previously selected by another experiment (ER: efficient and responsive; ENR: efficient and nonresponsive; IR: inefficient and responsive; INR: inefficient and nonresponsive) were grown in a growth chamber and fertilized with two 15N-labeled forms [(NH4)2SO4 (15N-NH4 +) or KNO3 (15N-NO3 −)]; soil was used as substrate. Plants were evaluated at three time points: 0, 24, and 72 h after 15N-fertilization. For the efficient genotypes (ER and ENR), the soil NH4 + levels were about 20% lower than those found for the inefficient genotypes (IR and INR) indicating greater N extraction by the plant. Nitrogen derived from fertilizer (NDFF) and 15 N recovery from fertilizer (15N RFF) in roots were influenced by the genotypes, in which responsive genotypes (ER and IR) presented a mean value 40% higher than the genotype INR, showing that greater absorption is more related to response than efficiency. Three days after N application, NDFF and 15N RFF from 15N-NH4 + were greater than 15N-NO3 − in 40% and 65% for the roots and aerial part, respectively. The results of this study confirmed that sugarcane presents preferential uptake of NH4 + N form 3 days after fertilization. The use of nitrification inhibitors can be considered for providing a longer NH4 + residence time in the soil, also contributing to augmenting the NUE in sugarcane.
{"title":"Preferential mineral N form uptake by sugarcane genotypes contrasting in nitrogen use efficiency","authors":"O. T. Kölln, B. N. Boschiero, H. Franco, Marina Camara Martins Soldi, G. Sanches, S. Castro, P. Trivelin","doi":"10.1017/S0014479722000229","DOIUrl":"https://doi.org/10.1017/S0014479722000229","url":null,"abstract":"Summary Ammonium has been reported as a ‘preferred’ nitrogen (N) source for sugarcane (Saccharum spp.), which can improve N use efficiency (NUE) in this crop. We aimed to evaluate the preferential uptake of ammonium and nitrate in sugarcane genotypes contrasting with NUE under controlled conditions. Four sugarcane genotypes previously selected by another experiment (ER: efficient and responsive; ENR: efficient and nonresponsive; IR: inefficient and responsive; INR: inefficient and nonresponsive) were grown in a growth chamber and fertilized with two 15N-labeled forms [(NH4)2SO4 (15N-NH4 +) or KNO3 (15N-NO3 −)]; soil was used as substrate. Plants were evaluated at three time points: 0, 24, and 72 h after 15N-fertilization. For the efficient genotypes (ER and ENR), the soil NH4 + levels were about 20% lower than those found for the inefficient genotypes (IR and INR) indicating greater N extraction by the plant. Nitrogen derived from fertilizer (NDFF) and 15 N recovery from fertilizer (15N RFF) in roots were influenced by the genotypes, in which responsive genotypes (ER and IR) presented a mean value 40% higher than the genotype INR, showing that greater absorption is more related to response than efficiency. Three days after N application, NDFF and 15N RFF from 15N-NH4 + were greater than 15N-NO3 − in 40% and 65% for the roots and aerial part, respectively. The results of this study confirmed that sugarcane presents preferential uptake of NH4 + N form 3 days after fertilization. The use of nitrification inhibitors can be considered for providing a longer NH4 + residence time in the soil, also contributing to augmenting the NUE in sugarcane.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48379479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-11DOI: 10.1017/S0014479722000291
Md. Ariful Islam, R. Bell, C. Johansen, M. Jahiruddin, M. E. Haque, W. Vance
Abstract Sustaining productivity of the rice-based cropping systems in the Eastern Indo-Gangetic Plain (EIGP) requires practices to reverse declining soil fertility resulting from excessive tillage and crop residue removal, while decreasing production costs and increasing farm profits. We hypothesize that the adoption of conservation agriculture (CA), involving minimum tillage, crop residue retention and crop rotation, can address most of these challenges. Therefore, the effects of crop establishment methods – strip planting (SP), bed planting (BP) and conventional tillage (CT); and levels of crop residue retention – high residue (HR) and low residue (LR) on individual crop yield, system yield and profitability were evaluated in a split-plot design over three cropping seasons in two field experiments (Alipur and Digram sites) with contrasting crops and soil types in the EIGP. The SP and BP of non-rice crops were rotated with non-puddled rice establishment; CT of non-rice crops was rotated with puddled transplanted rice. In the legume-dominated system (rice-lentil-mung bean), lentil yields were similar in SP and CT, while lower in BP in crop season 1. A positive effect of high residue over low residue was apparent by crop season 2 and persisted in crop season 3. In crop season 3, the lentil yield increased by 18–23% in SP and BP compared to CT. In the cereal-dominated system (rice-wheat-mung bean), significant yield increases of wheat in SP and BP (7–10%) over CT, and of HR (1–3%) over LR, were detected by crop season 3 but not before. Rice yields under CA practices (non-puddled and HR) were comparable with CT (puddled and LR) in both systems. Improved yield of lentil and wheat with CA was correlated with higher soil water content. The net income of SP increased by 25–28% for dry season crops as compared to CT and was equal with CT for rice cropping systems. Conservation agriculture practices provide opportunities for enhancing crop yield and profitability in intensive rice-based systems of the EIGP of Bangladesh.
{"title":"Conservation agriculture effects on yield and profitability of rice-based systems in the Eastern Indo-Gangetic Plain","authors":"Md. Ariful Islam, R. Bell, C. Johansen, M. Jahiruddin, M. E. Haque, W. Vance","doi":"10.1017/S0014479722000291","DOIUrl":"https://doi.org/10.1017/S0014479722000291","url":null,"abstract":"Abstract Sustaining productivity of the rice-based cropping systems in the Eastern Indo-Gangetic Plain (EIGP) requires practices to reverse declining soil fertility resulting from excessive tillage and crop residue removal, while decreasing production costs and increasing farm profits. We hypothesize that the adoption of conservation agriculture (CA), involving minimum tillage, crop residue retention and crop rotation, can address most of these challenges. Therefore, the effects of crop establishment methods – strip planting (SP), bed planting (BP) and conventional tillage (CT); and levels of crop residue retention – high residue (HR) and low residue (LR) on individual crop yield, system yield and profitability were evaluated in a split-plot design over three cropping seasons in two field experiments (Alipur and Digram sites) with contrasting crops and soil types in the EIGP. The SP and BP of non-rice crops were rotated with non-puddled rice establishment; CT of non-rice crops was rotated with puddled transplanted rice. In the legume-dominated system (rice-lentil-mung bean), lentil yields were similar in SP and CT, while lower in BP in crop season 1. A positive effect of high residue over low residue was apparent by crop season 2 and persisted in crop season 3. In crop season 3, the lentil yield increased by 18–23% in SP and BP compared to CT. In the cereal-dominated system (rice-wheat-mung bean), significant yield increases of wheat in SP and BP (7–10%) over CT, and of HR (1–3%) over LR, were detected by crop season 3 but not before. Rice yields under CA practices (non-puddled and HR) were comparable with CT (puddled and LR) in both systems. Improved yield of lentil and wheat with CA was correlated with higher soil water content. The net income of SP increased by 25–28% for dry season crops as compared to CT and was equal with CT for rice cropping systems. Conservation agriculture practices provide opportunities for enhancing crop yield and profitability in intensive rice-based systems of the EIGP of Bangladesh.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47984925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-01DOI: 10.1017/S0014479722000175
M. Sanogo, S. Coulibaly, Moussa Mariko, J. Witcombe
Abstract Single-cross pearl millet hybrids are widely grown in India, but this cultivar type has not been adopted in Africa. Hybrids from India have proven to be highly susceptible to downy mildew disease in Africa, the continent where the disease originated. We investigated an alternative strategy of growing topcross hybrids where both the parents are of African origin and both are only partially inbred. We investigated root characteristics – length, diameter, area, volume and dry weight – under drought stress and well-watered controlled conditions in genotypes that included potential parents of topcross hybrids. Several, including population Civarex 06_05, had better developed roots under drought while also having good roots under more favourable conditions. Some of these genotypes were backrossed to a male-sterile line based on the A4 cytoplasm to produce male-sterile populations with stable male sterility. Civarex 06_05 had good combining ability when used as a female parent and produced high-yielding topcross hybrids. Two of the topcross hybrids were on restorer populations Toroniou, originating from Mali, and Maiwa from Nigeria. On the experimental station and in farmers’ fields, one was much superior in yield to the best local alternatives and both had superior downy mildew resistance. Current efforts on the seed production of these topcross hybrids are described, and the constraints to the commercialisation in Mali of promising topcross hybrids are discussed.
{"title":"Topcross pearl millet hybrids for Africa: A case study for Mali","authors":"M. Sanogo, S. Coulibaly, Moussa Mariko, J. Witcombe","doi":"10.1017/S0014479722000175","DOIUrl":"https://doi.org/10.1017/S0014479722000175","url":null,"abstract":"Abstract Single-cross pearl millet hybrids are widely grown in India, but this cultivar type has not been adopted in Africa. Hybrids from India have proven to be highly susceptible to downy mildew disease in Africa, the continent where the disease originated. We investigated an alternative strategy of growing topcross hybrids where both the parents are of African origin and both are only partially inbred. We investigated root characteristics – length, diameter, area, volume and dry weight – under drought stress and well-watered controlled conditions in genotypes that included potential parents of topcross hybrids. Several, including population Civarex 06_05, had better developed roots under drought while also having good roots under more favourable conditions. Some of these genotypes were backrossed to a male-sterile line based on the A4 cytoplasm to produce male-sterile populations with stable male sterility. Civarex 06_05 had good combining ability when used as a female parent and produced high-yielding topcross hybrids. Two of the topcross hybrids were on restorer populations Toroniou, originating from Mali, and Maiwa from Nigeria. On the experimental station and in farmers’ fields, one was much superior in yield to the best local alternatives and both had superior downy mildew resistance. Current efforts on the seed production of these topcross hybrids are described, and the constraints to the commercialisation in Mali of promising topcross hybrids are discussed.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46463807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-01DOI: 10.1017/S0014479722000102
Gift Ndengu, P. Mponela, B. Chataika, L. Desta, R. Chirwa, Gudeta G. Sileshi
Summary In sub-Saharan Africa (SSA), farmers intercrop common beans with maize but apply inorganic or organic fertilisers targeting only maize. Effects of this practice on bush bean yield have not been fully evaluated with respect to input use and compatibility when intercropped with maize. An on-farm trial managed by smallholder community members was conducted to assess the influence of various soil fertility management options and cropping systems on the yield of two bush bean genotypes (SER45 and SER83) in two agro-ecological zones of Malawi. The farmer-managed trials were laid out in split-plot design, with the bean genotypes as main plots and a combination of the soil fertility management options (i.e., no input, manure, fertiliser and fertiliser + manure) and cropping systems (i.e., sole crop and intercrop) as subplots. The trials were affected by terminal drought and dry spells, but results show that manure and fertiliser application enhanced the resilience of the drought-tolerant bean genotypes. The genotype SER45 was responsive to manure application in the sole crop, giving a 44.4% yield increase over no-manure application. In sole cropping with fertiliser plus manure, bean yields improved by 40.1% for SER45 and 78.3% for SER83 relative to the no-input control. Although sole cropping had higher bean yields, the treatment with manure and fertiliser had a higher land equivalence ratio for intercrop of 1.54 for SER45 and 1.32 for SER83 over sole cropping. These results show that, under smallholder farmer management, the climate adaptability of bush bean genotypes could be enhanced by the combined application of organic and inorganic fertilisers in maize–bean intercrop. The combined application also enhances whole-farm productivity of the common maize–bean intercrop practice than monocrop, hence is of benefit to most low-input smallholder farmers of SSA.
{"title":"Effect of combining organic manure and inorganic fertilisers on maize–bush bean intercropping","authors":"Gift Ndengu, P. Mponela, B. Chataika, L. Desta, R. Chirwa, Gudeta G. Sileshi","doi":"10.1017/S0014479722000102","DOIUrl":"https://doi.org/10.1017/S0014479722000102","url":null,"abstract":"Summary In sub-Saharan Africa (SSA), farmers intercrop common beans with maize but apply inorganic or organic fertilisers targeting only maize. Effects of this practice on bush bean yield have not been fully evaluated with respect to input use and compatibility when intercropped with maize. An on-farm trial managed by smallholder community members was conducted to assess the influence of various soil fertility management options and cropping systems on the yield of two bush bean genotypes (SER45 and SER83) in two agro-ecological zones of Malawi. The farmer-managed trials were laid out in split-plot design, with the bean genotypes as main plots and a combination of the soil fertility management options (i.e., no input, manure, fertiliser and fertiliser + manure) and cropping systems (i.e., sole crop and intercrop) as subplots. The trials were affected by terminal drought and dry spells, but results show that manure and fertiliser application enhanced the resilience of the drought-tolerant bean genotypes. The genotype SER45 was responsive to manure application in the sole crop, giving a 44.4% yield increase over no-manure application. In sole cropping with fertiliser plus manure, bean yields improved by 40.1% for SER45 and 78.3% for SER83 relative to the no-input control. Although sole cropping had higher bean yields, the treatment with manure and fertiliser had a higher land equivalence ratio for intercrop of 1.54 for SER45 and 1.32 for SER83 over sole cropping. These results show that, under smallholder farmer management, the climate adaptability of bush bean genotypes could be enhanced by the combined application of organic and inorganic fertilisers in maize–bean intercrop. The combined application also enhances whole-farm productivity of the common maize–bean intercrop practice than monocrop, hence is of benefit to most low-input smallholder farmers of SSA.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47671885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-01DOI: 10.1017/S0014479722000266
M. Rakocevic, Paulo Eduardo R. Marchiori, F. C. Zambrosi, E. Machado, A. Maia, R. V. Ribeiro
Abstract Drought is considered as the major environmental stress affecting coffee production, and high phosphorus (P) supply may alleviate the drought effects on crop metabolism. Here, we hypothesized that high P supply would mitigate the impacts of drought on Arabica coffee physiology, morphology, and biomass accumulation. Potted Arabica coffee plants were grown under two P levels: the recommended P fertilization (P), and twice the recommended fertilization (+P), and two water regimes: well-watered and water withholding for 32 days. Leaf, stem, and root P concentrations were increased under +P, with plants showing higher photosynthesis and growth than the ones receiving the recommended P dose. Higher plant growth under high P supply seems to upregulate leaf photosynthesis through the source–sink relationship. Under the water deficit, the reduction of leaf photosynthesis, stomatal conductance, transpiration, water use efficiency, carboxylation efficiency, chlorophyll content, number of plagiotropic branches, plant leaf area, and vegetative biomass production was similar comparing plants fertilized with the recommended P to those supplied with +P. However, Arabica coffee trees under high P supply and water deficit presented morphological and physiological traits similar to plants under well-watered and recommended P fertilization.
{"title":"High phosphorus supply enhances leaf gas exchange and growth of young Arabica coffee plants under water deficit","authors":"M. Rakocevic, Paulo Eduardo R. Marchiori, F. C. Zambrosi, E. Machado, A. Maia, R. V. Ribeiro","doi":"10.1017/S0014479722000266","DOIUrl":"https://doi.org/10.1017/S0014479722000266","url":null,"abstract":"Abstract Drought is considered as the major environmental stress affecting coffee production, and high phosphorus (P) supply may alleviate the drought effects on crop metabolism. Here, we hypothesized that high P supply would mitigate the impacts of drought on Arabica coffee physiology, morphology, and biomass accumulation. Potted Arabica coffee plants were grown under two P levels: the recommended P fertilization (P), and twice the recommended fertilization (+P), and two water regimes: well-watered and water withholding for 32 days. Leaf, stem, and root P concentrations were increased under +P, with plants showing higher photosynthesis and growth than the ones receiving the recommended P dose. Higher plant growth under high P supply seems to upregulate leaf photosynthesis through the source–sink relationship. Under the water deficit, the reduction of leaf photosynthesis, stomatal conductance, transpiration, water use efficiency, carboxylation efficiency, chlorophyll content, number of plagiotropic branches, plant leaf area, and vegetative biomass production was similar comparing plants fertilized with the recommended P to those supplied with +P. However, Arabica coffee trees under high P supply and water deficit presented morphological and physiological traits similar to plants under well-watered and recommended P fertilization.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46110681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-28DOI: 10.1017/S0014479722000242
J. Pezzopane, A. C. de Campos Bernardi, C. Bosi, Orlando Sengling, W. L. Bonani, H. B. Brunetti, P. M. Santos
Abstract In intensive livestock production systems, estimating forage production and its nutritive value can assist farmers in optimizing pasture management, stocking rate, and feed supplementation to animals. In this study, we aimed to use vegetation indices, determined using a proximal canopy reflectance sensor, to estimate the forage mass, crude protein content, and nitrogen in live forage of Marandu palisadegrass (Urochloa brizantha). Pasture canopy reflectance was measured at three wavelengths (670, 720, and 760 nm) using a Crop Circle device equipped with an ACS-430 sensor. Total forage mass, plant-part composition, leaf area index (LAI), and crude protein content were assessed during 14 growth cycles in a pasture under four management regimes, comprising different combinations of two N fertilization rates and two irrigation schedules. For each forage assessment, pasture canopy reflectance data were used to calculate the following vegetation indices: normalized difference vegetation index, normalized difference red edge, simple ratio index (SRI), modified simple ratio, and chlorophyll index. In addition, we also performed analyses of the linear and exponential regressions between vegetation indices and total forage mass, leaf + stem mass, leaf mass, LAI, crude protein content, and nitrogen in live forage. The best estimates were achieved for total forage mass, leaf + stem mass, leaf mass, and nitrogen in live forage using SRI (R2 values between 0.72 and 0.79). When estimating pasture productive variables (total forage mass, leaf + stem mass, leaf mass, and LAI) from SRI, the equations showed R2 values between 0.69 (leaf mass) and 0.74 (LAI) and relative errors ranging from 19% to 21%. For each of the water and nitrogen supply conditions evaluated, this index facilitated the monitoring of forage mass time series and nitrogen in live forage and the extraction of this nutrient by the pasture.
{"title":"Estimating productivity and nutritive value of Marandu palisadegrass using a proximal canopy reflectance sensor","authors":"J. Pezzopane, A. C. de Campos Bernardi, C. Bosi, Orlando Sengling, W. L. Bonani, H. B. Brunetti, P. M. Santos","doi":"10.1017/S0014479722000242","DOIUrl":"https://doi.org/10.1017/S0014479722000242","url":null,"abstract":"Abstract In intensive livestock production systems, estimating forage production and its nutritive value can assist farmers in optimizing pasture management, stocking rate, and feed supplementation to animals. In this study, we aimed to use vegetation indices, determined using a proximal canopy reflectance sensor, to estimate the forage mass, crude protein content, and nitrogen in live forage of Marandu palisadegrass (Urochloa brizantha). Pasture canopy reflectance was measured at three wavelengths (670, 720, and 760 nm) using a Crop Circle device equipped with an ACS-430 sensor. Total forage mass, plant-part composition, leaf area index (LAI), and crude protein content were assessed during 14 growth cycles in a pasture under four management regimes, comprising different combinations of two N fertilization rates and two irrigation schedules. For each forage assessment, pasture canopy reflectance data were used to calculate the following vegetation indices: normalized difference vegetation index, normalized difference red edge, simple ratio index (SRI), modified simple ratio, and chlorophyll index. In addition, we also performed analyses of the linear and exponential regressions between vegetation indices and total forage mass, leaf + stem mass, leaf mass, LAI, crude protein content, and nitrogen in live forage. The best estimates were achieved for total forage mass, leaf + stem mass, leaf mass, and nitrogen in live forage using SRI (R2 values between 0.72 and 0.79). When estimating pasture productive variables (total forage mass, leaf + stem mass, leaf mass, and LAI) from SRI, the equations showed R2 values between 0.69 (leaf mass) and 0.74 (LAI) and relative errors ranging from 19% to 21%. For each of the water and nitrogen supply conditions evaluated, this index facilitated the monitoring of forage mass time series and nitrogen in live forage and the extraction of this nutrient by the pasture.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48365617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-27DOI: 10.1017/S0014479722000254
Sucharat Butphu, W. Kaewpradit
Summary An on-farm field experiment was conducted in northeastern Thailand to assess the effects of different eucalyptus biochar (BC) application rates, in combination with mineral fertilizers, on upland rice and a succeeding crop of sugarcane on sandy soil. Soil mineral N and greenhouse gas emissions were also evaluated. The field experiment consisted of three treatments: no biochar (BC0), 3.1 Mg ha−1 of biochar (BC1), and 6.2 Mg ha−1 of biochar (BC2). All treatments received the same recommended fertilizer rate. Soil mineral N, and emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were monitored after BC application. The results revealed that the BC2 treatment caused lower soil mineral N content than that of the BC0 treatment during the upland rice period. During the sugarcane period, the BC2 treatment induced a greater soil mineral N content than the BC1 treatment but had no significant difference from the BC0 treatment. The BC2 treatment resulted in significantly lower cumulative CH4 and N2O emissions than the BC0 treatment during the upland rice period. In conclusion, we found that the BC2 treatment alleviated the global warming potential from CH4 and N2O emissions throughout the experiment, causing slight changes in soil N availability in the upland rice–sugarcane cropping system.
{"title":"Impacts of eucalyptus biochar application on greenhouse gas emission from an upland rice–sugarcane cropping system on sandy soil","authors":"Sucharat Butphu, W. Kaewpradit","doi":"10.1017/S0014479722000254","DOIUrl":"https://doi.org/10.1017/S0014479722000254","url":null,"abstract":"Summary An on-farm field experiment was conducted in northeastern Thailand to assess the effects of different eucalyptus biochar (BC) application rates, in combination with mineral fertilizers, on upland rice and a succeeding crop of sugarcane on sandy soil. Soil mineral N and greenhouse gas emissions were also evaluated. The field experiment consisted of three treatments: no biochar (BC0), 3.1 Mg ha−1 of biochar (BC1), and 6.2 Mg ha−1 of biochar (BC2). All treatments received the same recommended fertilizer rate. Soil mineral N, and emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were monitored after BC application. The results revealed that the BC2 treatment caused lower soil mineral N content than that of the BC0 treatment during the upland rice period. During the sugarcane period, the BC2 treatment induced a greater soil mineral N content than the BC1 treatment but had no significant difference from the BC0 treatment. The BC2 treatment resulted in significantly lower cumulative CH4 and N2O emissions than the BC0 treatment during the upland rice period. In conclusion, we found that the BC2 treatment alleviated the global warming potential from CH4 and N2O emissions throughout the experiment, causing slight changes in soil N availability in the upland rice–sugarcane cropping system.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48256251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-25DOI: 10.1017/S0014479722000126
L. Tamene, W. Abera, E. Bendito, T. Erkossa, Meklit Tariku, Habtamu Sewnet, D. Tibebe, Jemal Sied, G. Feyisa, M. Wondie, K. Tesfaye
Abstract Ethiopia has heterogeneous topographic, climatic and socio-ecological systems. Recommendations of agricultural inputs and management practices based on coarse domains such as agro-ecological zones (AEZ) may not lead to accurate targeting, mainly due to large intra-zone variations. The lack of well-targeted recommendations may contribute to the underperformance of promising technologies. Therefore, there is a need to define units where similar environmental and biophysical features prevail, based on which specific recommendations can be made for similar response units (SRUs). We used unsupervised machine learning algorithms to identify areas of high similarity or homogeneous zones called ‘SRUs’ that can guide the targeting of agricultural technologies. SRUs are landscape entities defined by integrating relevant environmental covariates with the intention to identify areas of similar responses. Using environmental spatial data layers such as edaphic and ecological variables for delineation of the SRUs, we applied K- and X-means clustering techniques to generate various granular levels of zonation and define areas of high similarity. The results of the clustering were validated through expert consultation and by comparison with an existing operational AEZ map of Ethiopia. We also augmented validation of the heterogeneity of the SRUs by using field-based crop response to fertiliser application experimental data. The expert consultation highlighted that the SRUs can provide improved clustering of areas of high similarity for targeting interventions. Comparison with the AEZ map indicated that SRUs with the same number of AEZ units captured heterogeneity better with less within-cluster variability of the former. In addition, SRUs show lower within-cluster variability to optimal crop response to fertiliser application compared with AEZs with the same number of classes. This implies that the SRUs can be used for refined agricultural input and technology targeting. The work in this study also developed an operational framework that users can deploy to fetch data from the cloud and generate SRUs for their areas of interest.
{"title":"Data-driven similar response units for agricultural technology targeting: An example from Ethiopia","authors":"L. Tamene, W. Abera, E. Bendito, T. Erkossa, Meklit Tariku, Habtamu Sewnet, D. Tibebe, Jemal Sied, G. Feyisa, M. Wondie, K. Tesfaye","doi":"10.1017/S0014479722000126","DOIUrl":"https://doi.org/10.1017/S0014479722000126","url":null,"abstract":"Abstract Ethiopia has heterogeneous topographic, climatic and socio-ecological systems. Recommendations of agricultural inputs and management practices based on coarse domains such as agro-ecological zones (AEZ) may not lead to accurate targeting, mainly due to large intra-zone variations. The lack of well-targeted recommendations may contribute to the underperformance of promising technologies. Therefore, there is a need to define units where similar environmental and biophysical features prevail, based on which specific recommendations can be made for similar response units (SRUs). We used unsupervised machine learning algorithms to identify areas of high similarity or homogeneous zones called ‘SRUs’ that can guide the targeting of agricultural technologies. SRUs are landscape entities defined by integrating relevant environmental covariates with the intention to identify areas of similar responses. Using environmental spatial data layers such as edaphic and ecological variables for delineation of the SRUs, we applied K- and X-means clustering techniques to generate various granular levels of zonation and define areas of high similarity. The results of the clustering were validated through expert consultation and by comparison with an existing operational AEZ map of Ethiopia. We also augmented validation of the heterogeneity of the SRUs by using field-based crop response to fertiliser application experimental data. The expert consultation highlighted that the SRUs can provide improved clustering of areas of high similarity for targeting interventions. Comparison with the AEZ map indicated that SRUs with the same number of AEZ units captured heterogeneity better with less within-cluster variability of the former. In addition, SRUs show lower within-cluster variability to optimal crop response to fertiliser application compared with AEZs with the same number of classes. This implies that the SRUs can be used for refined agricultural input and technology targeting. The work in this study also developed an operational framework that users can deploy to fetch data from the cloud and generate SRUs for their areas of interest.","PeriodicalId":12245,"journal":{"name":"Experimental Agriculture","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42002361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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