Farmers' evaluation and analysis of the factors determining the adoption of improved farm technology are essential to elicit what varietals characteristics motivate farmers to adopt or reject improved varieties and t...Farmers' evaluation and analysis of the factors determining the adoption of improved farm technology are essential to elicit what varietals characteristics motivate farmers to adopt or reject improved varieties and the technology. The main objective of the study was to elicit farmers' criteria for selecting rice varieties and the factors determining adoption of NERICA varieties in the study areas. The data used for this study were collected from 600 farmers in Ekiti, Kaduna, Nassarawa, Ogun, Ondo, and Taraba States of Nigeria through farming household survey conducted from August to September 2009. The main instruments for data collection were well-structured questionnaires administered in each state. This study utilized descriptive statistics, such as means, frequency and percentages; and Tobit regression model were used to analyze the data collected. The results revealed that field days attendance was very low in the study areas and was similar across states; and this may limit their participation in exchange of ideas and in sharing of knowledge and experience of improved technology. The small farm size and subsequently low output could adversely affect rice production in the country and thus prevent the country from attaining self-sufficiency in rice production. Farmers grow an assortment of both local and improved rice varieties and the most important criteria across the states were high yield, tillering and logging resistance. There was progressive increase in the proportion of land given to NERICA rice cultivation since 2004. This suggests that there is increase in the adoption rate of NERICA varieties across states. Level of formal education, farm size, access to credit, rice income, farm income and level of awareness of NERICA varieties positively and significantly determined NERICA rice adoption. Base on these, we recommend that government should aim at policies geared towards providing incentives to encourage all stakeholders to improve productivity in rice production. Incentives, such as provision of micro credit and implementation of subsidy on inputs like fertilizer and seed, would go a long way in boosting rice production in the study area.展开更多
Rice as staple food is the most important and valuable cereal crop in Cameroon, particularly in rural areas where poor population cannot afford to cook and eat at their convenience. With the outbreak of Nerica varieti...Rice as staple food is the most important and valuable cereal crop in Cameroon, particularly in rural areas where poor population cannot afford to cook and eat at their convenience. With the outbreak of Nerica varieties, it is important to evaluate and compare their nutritional and mineral properties to those of the local ones prior to their vulgarisation. Therefore, some nutritional and mineral properties of 4 Nerica and a local seeds varieties used in this study were harvested from control (T0), chemical fertilizer (TE), mycorrhiza (TM) applied plants, or their mixture (TEM). These seeds originating from Wakwa and/or Yagoua experimental sites were assessed and compared in a split-plot design (4 × 5) × 3 between treatments (4) and varieties (5). The local DIR-95 variety had values close to those of Nerica varieties in all the parameters assessed. Protein contents ranged from 17.66% - 24.35%, and was higher than those reported in rice samples elsewhere. All the studied varieties were classified as high amylose rice, and therefore, their textures in cooked form should be less sticky and harder, which is convenient to the diet behavior of many consumers. The relative low Fe content in Nerica rice suggest that these varieties may be resistant to Fe accumulation in seeds. The P, N, Mg contents were found to be more elevated in seeds harvested from mycorrhiza or chemical fertilizer applied plants, with Nerica seeds variety FKR62-N as the best of all in nutrients mineral and nutritional compositions. These results confirm varietal and site influences on proximate and mineral contents in the studied rice varieties.展开更多
ISFM (integrated soil fertility management) involving annual sequencing of dual-purpose early-maturing first crop of cowpeas with biomass incorporation before seeding second crop of early-maturing NERICA (New Rice ...ISFM (integrated soil fertility management) involving annual sequencing of dual-purpose early-maturing first crop of cowpeas with biomass incorporation before seeding second crop of early-maturing NERICA (New Rice for Africa) was evaluated to enhance rice productivity and soil-nitrogen. Five dual-purpose early-maturing cowpea cultivars and local cultivar (Katche) were seeded early in the wet season in five farmers' fields at Ouake (9046' N, 1°35′ E, highly degraded-savanna), Benin. After pod harvest, cowpea residues were minimally worked into the soil using minimum tillage with hand-hoe and seeded with early-maturing, resilient NERICA8 rice that received either 20 kg N/ha or zero-N. Cowpea grain yield averaged 0.1-0.3 Mg/ha, and mean aboveground cowpea biomass produced and recycled was 0.54-0.64 Mg/ha among best cultivars (IT97-568-11 and IT89KD-288). NERICA8 seeded after cowpea cv. IT97-568-11 and supplied with 20N gave the greatest grain yield of about 2.0 Mg/ha, accounting for 500% heavier grains than fallow-rice rotation with zero-N. Mineral-N dynamics monitored under NERICA8 in year 2 showed that previous IT97-568-11 plots had the highest mineral-N at tillering which persisted till panicle initiation stage. The adoption of an ISFM comprising annual cowpea-NERICA sequence by smallholder rice farmers could enhance productivity and improve N-supply in fragile savannas.展开更多
The responses of five inter-specific lowland rice cultivars (NERICA-L-19, NERICA-L-20, NERICA-L-41, NERICA-L-42, and NERICA-L-60) and four improved Oryza sativa cultivars (FKR 19, BW 348-1, WITA 4, and SIPI 6923033...The responses of five inter-specific lowland rice cultivars (NERICA-L-19, NERICA-L-20, NERICA-L-41, NERICA-L-42, and NERICA-L-60) and four improved Oryza sativa cultivars (FKR 19, BW 348-1, WITA 4, and SIPI 6923033) to levels of phosphorus and nitrogen fertilization were compared on a Typic Natrustalfat Kadawa in the Nigerian Sudan Savanna in 2006 and 2007 The responses of the NERICA-L eultivars to N and P fertilization were similar to the O. sativa cultivars. In a dry year (2007), the NERICA-L cultivars gave higher yields than O. sativa cultivars. Phosphorus level did not significantly affect crop physiology, yield, and yield components of all the cultivars. Pooled across cultivars, N and P levels, days to panicle initiation, mid-flowering and maturity were, respectively delayed by 17.0, 15.6 and 6.4 days in 2007 compared to 2006. NERICA-L-42 and NERICA-L-41 were the most stable, exhibiting the least difference in duration to maturity between the two years (3.5 and 4.4 days, respectively), and could therefore be more adapted to rain-fed environments prone to frequent droughts. Increasing N levels from 0 to 120 kg hal produced yield increments of 62.9 and 37.2% in 2006 and 2007, respectively. Cultivars FKR 19 and WITA 4 gave higher yields in 2006 (3940 and 3542 kg ha^-1, respectively), while in 2007, NERICA-L-42, NERICA-L^-19 and NERICA-L-20 ranked among the highest in grain yield (3935, 3807 and 3726 kg hal, respectively) and could be recommended to resource-poor farmers. a展开更多
A two-year field experiment was conducted to evaluate the influence of nitrogen (0, 30, 60, and 120 kg N ha^-1) and phosphorus (0, 30, and 60 kg P2O5 ha^-1) application on grain yield and yield components of five ...A two-year field experiment was conducted to evaluate the influence of nitrogen (0, 30, 60, and 120 kg N ha^-1) and phosphorus (0, 30, and 60 kg P2O5 ha^-1) application on grain yield and yield components of five New Rice for Africa (NERICA) cultivars, their parents, and a check on a degraded soil in the moist savanna of Nigeria. Nerica 14 recorded the highest grain yield of 1.3 mg halcompared to the other NERICA cultivars. It also produced significantly (P 〈 0.05) longer panicles (19.24 cm), higher sink capacity as determined by thousand-kernel weight (30.3 g), and a higher potential for partitioning photosynthates (45.15%) into grains than the other cultivars. N × P interaction effect on grain yield was significant (P 〈 0.05) with moderate P (60 kg P2O5 ha^1) and moderate N (60 kg N ha^-1) resulting in optimum grain yield (1.7 mg ha^-1). Thus, moderate N and P were recommended for the production of NERICA varieties in low-input smallholder upland rice production systems of the moist savanna of Nigeria.展开更多
A two-year on-farm study was carried out at Eglime in the moist savanna (MS) and Ouake in the dry savanna (DS) of Benin to evaluate the contribution of inoculation of dual-purpose soybean varieties to grain yield ...A two-year on-farm study was carried out at Eglime in the moist savanna (MS) and Ouake in the dry savanna (DS) of Benin to evaluate the contribution of inoculation of dual-purpose soybean varieties to grain yield of upland NERICA rice fertilized with low N level. In 2005, four dual-purpose, promiscuous soybean varieties (cv. TGx1440-IE; TG×1448-2E; TG×1019-2EB; and TG×1844-18E), and a popular improved variety (cv. Jupiter) were sown in 12 farmer fields with and without Bradyrhizobium japonicum inoculation. There was also land which was left fallow that acted as the control. In 2006, upland interspecific rice (NERICA 1) was sown in all the plots and supplied with 15 kg N haL. Dry matter yield, N accumulation, and net N-balance were significantly enhanced by over 40% with inoculation of cv. TG× 1844-18E than non-inoculation in the DS in comparison to other cultivars. There were no significant effects of inoculation of previous soybean cultivars on soybean grain yield and on the succeeding NERICA rice yield. Averaged over inoculation, previous cv. TG× 1019-2EB plots supplied with only 15 kg N hal gave the highest grain yield, more than twice the yield of control plots in the DS, possibly because of significant production of higher tillers, panicles and harvest index than the other cultivars; and it could be recommended for upland rice-based system for NERICA production.展开更多
Eritrean farmers can cultivate rice by harvesting runoff from >82% available non-agricultural land in agricultural watersheds for crop use and reducing percolation through optimization of tillage. Experiments were ...Eritrean farmers can cultivate rice by harvesting runoff from >82% available non-agricultural land in agricultural watersheds for crop use and reducing percolation through optimization of tillage. Experiments were conducted with NERICA rice, N11, to optimize irrigation requirements and puddling and compaction to reduce percolation. Experimental field was adjacent to Anseba River at downstream end of the watershed and a pond on the upstream to intercept runoff. Irrigation treatments were runoff farming with maximum runoff application depth of 10 mm (I<sub>1</sub>), and 50 mm irrigation two (I<sub>2</sub>), five (I<sub>3</sub>), and seven (I<sub>4</sub>) days after disappearance of ponded water in main plots and puddling by one (T<sub>1</sub>), two (T<sub>2</sub>) and three (T<sub>3</sub>) passes of puddler and compaction by three (T<sub>4</sub>), four (T<sub>5</sub>) and five (T<sub>6</sub>) passes of 600 kg roller in sub plots in 3 replications. Soil profile was loam in the surface 0.45 m and coarse sandy loam below forming porous belt. Soil submergence was difficult to maintain, but water table was developed in soil profile due to inflow of seepage from the river and pond. Depth to the water table was within 1.5 ± 0.1 m for >2 months and receded down to 1.7 m by crop maturity. Soil wetness was near field capacity around 0.7 m depth and increased below due to natural sub-irrigation from the water table. Rice roots penetrated 0.8 m in the puddled plots and 0.7 m in the compacted plots. Residual soil moisture of 135 - 146 mm·m<sup>-1</sup> after rice harvesting provides opportunity for planting rapeseed mustered following rice. Puddling was superior to compaction in loam soil. Puddling twice and irrigation 50 mm 7 days after ponded water vanished from surface was sufficient for optimum rice grain yield of 4346 kg·ha<sup>-1</sup> and straw yield of 4458 kg·ha<sup>-1</sup>. Optimum puddling and irrigation schedules reduced crop duration by 6 days without significantly affecting yield. Production function showed that rice grain yield of 4789 kg ha<sup>-1</sup> could be obtained by 1009 mm applied water through rainfall and irrigation.展开更多
Sustainable rice production in Sierra Leone faces serious constraints due to soil acidity, low cation exchange capacity, low nutrient contents accelerated mineralization of soil organic matter and soil loss by erosion...Sustainable rice production in Sierra Leone faces serious constraints due to soil acidity, low cation exchange capacity, low nutrient contents accelerated mineralization of soil organic matter and soil loss by erosion (particularly on the uplands). One possible approach to addressing the soil constraints to rice production both on uplands and lowlands of Sierra Leone is the recycling of rice residues through biochar production and application to soils. A pot experiment was conducted to investigate the effects of application of biochar from rice residues on (i) soil physicochemical properties and (ii) the early growth characteristics of two rice varieties, NERICA L19 and ROK3. The experiment was arranged in a completely randomized design (CRD) with two biochar levels (0 and 15 g/kg soil) and two rice varieties in three replications. For the biochar treated soils (+biochar), 75 g rice straw biochar was applied to 5 kg air-dry soil (15 kg biochar/kg soil), mixed thoroughly and placed into perforated black polythene bags. Seeds of two rice varieties, NERICA L19 and ROK3 were planted on the treated and untreated soils for eight weeks. Application of biochar improved available phosphorus, exchangeable cations and cation exchange capacity in biochar treated soils compared to the control soil without biochar. Plant height, tiller number, and dry biomass weight of both rice varieties grown in soils amended with rice straw biochar were significantly higher than those on untreated soils. The most remarkable increase in plant growth characteristics as a result of biochar addition to soil was reflected in the biomass yield and tiller numbers. Dry shoot biomass for ROK3 rice variety varied significantly from a mean of 3.5 g (control) to 26.2 g (+biochar) while tiller numbers significantly varied from 10 (control) to 29.6 (+biochar). Similarly, for NERICA L19 rice variety, dry shoot biomass increased significantly from 4.5 g (control) to 22.7 g (+biochar) while tiller numbers increased significantly from a mean of 12.3 (control) to 30 (+biochar). Thus converting rice residues to biochar and applying to soil holds promise for improving rice production in Sierra Leone.展开更多
Rice is not cultivated in Eritrea because of its high water requirements and arid to semiarid conditions. However, most agricultural watersheds in Eritrea are associated with >80% non-agricultural lands, which prod...Rice is not cultivated in Eritrea because of its high water requirements and arid to semiarid conditions. However, most agricultural watersheds in Eritrea are associated with >80% non-agricultural lands, which produce significant runoff that can be diverted for use by rice crop. Experiments were conducted at Hamelmalo Agricultural College, Eritrea, using four NERICA rice varieties viz. N1, N4, N10 and N11 under rainfed (Io) and limited supplementary irrigations (I) in 3 replications. Results showed that plants were taller under limited irrigations than rainfed. Among the 4 varieties, N11 was most affected by water stress in which plant height was 0.72 m under rainfed and 0.89 m under limited irrigations. Effective tillers were highest (6) in N11 under limited irrigations and lowest (2) in N10 under rainfed. Panicles were shorter (0.20 m) in N10 and longer (0.23 - 0.24 m) in N1 and N11. Irrigations delayed maturity by 6 - 15 days. Water use by N11 was higher both under limited irrigations (987 mm) and rainfed (477 mm) and lower by N10 under rainfed (457 mm). Root growth in all the varieties was better under irrigations (I) than rainfed (Io). Roots were limited to 0.7 m depth under rainfed (Io) but grew down to 0.8 m in N1, N4 and N11 under limited irrigations (I). Roots in N10 were limited to 0.5 m depth under Io and 0.7 m under I. More than 63% roots in N10 were in 0 - 0.1 m layer under rainfed as against less than 55% under limited irrigations. In lower layers, roots under Io were more in N4 than others, which is a beneficial trait for better performance under semiarid environments. Roots in N11 were better and uniformly distributed in lower layers under irrigated conditions. Rooting patterns and grain yields showed that N11 was most responsive to irrigations but susceptible to water stress and N4 was best under rainfed followed by N10. N4 was next to N11 under irrigated conditions.展开更多
Rainfed Aus rice is a popular conventional rice cultivation technique that through appropriate variety selection can accelerate the benefits of the farmer. On this context, an experiment was carried out at the researc...Rainfed Aus rice is a popular conventional rice cultivation technique that through appropriate variety selection can accelerate the benefits of the farmer. On this context, an experiment was carried out at the research field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur1706 from April to August in 2014 to evaluate yield performance of some Aus rice varieties under rainfed condition. The experiment was laid out in a split plot design with three replications. The experiment consisted of two sets of treatments: water regime as irrigated (irrigation when necessary) and rainfed (dependent on rainfall) in the main plot and 15 varieties into sub-plots. It was revealed that yield and yield contributing characters were significantly influenced by water regime, variety and their interaction. The traits like number of effective tillers and non-effective tillers·hill-1, number of filled grains and unfilled grains panicle-1, panicle length, test weight, grain yield and harvest index were higher in irrigated crops compared to rainfed. Considering the performance of yield, the highest grain yield recorded in BRRI dhan27 (irrigated-2.47 t·ha-1 and rainfed-2.26 t·ha-1) followed by BRRI dhan55 (irrigated-1.95 t·ha-1 and rainfed-1.88 t·ha-1), BRRI dhan48 and BRRI dhan43 under both irrigated and rainfed treatment. BRRI dhan27 ranked the top under both irrigated and rainfed conditions, however the relative yield was maximum in BRRI dhan55 (reduction was only 3.59%) followed by Nerica10. Hence, considering the yield stability and absolute yield performance, BRRI dhan27 may be considered favorably cultivable for Aus season in Bangladesh followed by BRRI dhan55, BRRI dhan48 and BRRI dhan43.展开更多
文摘Farmers' evaluation and analysis of the factors determining the adoption of improved farm technology are essential to elicit what varietals characteristics motivate farmers to adopt or reject improved varieties and the technology. The main objective of the study was to elicit farmers' criteria for selecting rice varieties and the factors determining adoption of NERICA varieties in the study areas. The data used for this study were collected from 600 farmers in Ekiti, Kaduna, Nassarawa, Ogun, Ondo, and Taraba States of Nigeria through farming household survey conducted from August to September 2009. The main instruments for data collection were well-structured questionnaires administered in each state. This study utilized descriptive statistics, such as means, frequency and percentages; and Tobit regression model were used to analyze the data collected. The results revealed that field days attendance was very low in the study areas and was similar across states; and this may limit their participation in exchange of ideas and in sharing of knowledge and experience of improved technology. The small farm size and subsequently low output could adversely affect rice production in the country and thus prevent the country from attaining self-sufficiency in rice production. Farmers grow an assortment of both local and improved rice varieties and the most important criteria across the states were high yield, tillering and logging resistance. There was progressive increase in the proportion of land given to NERICA rice cultivation since 2004. This suggests that there is increase in the adoption rate of NERICA varieties across states. Level of formal education, farm size, access to credit, rice income, farm income and level of awareness of NERICA varieties positively and significantly determined NERICA rice adoption. Base on these, we recommend that government should aim at policies geared towards providing incentives to encourage all stakeholders to improve productivity in rice production. Incentives, such as provision of micro credit and implementation of subsidy on inputs like fertilizer and seed, would go a long way in boosting rice production in the study area.
文摘Rice as staple food is the most important and valuable cereal crop in Cameroon, particularly in rural areas where poor population cannot afford to cook and eat at their convenience. With the outbreak of Nerica varieties, it is important to evaluate and compare their nutritional and mineral properties to those of the local ones prior to their vulgarisation. Therefore, some nutritional and mineral properties of 4 Nerica and a local seeds varieties used in this study were harvested from control (T0), chemical fertilizer (TE), mycorrhiza (TM) applied plants, or their mixture (TEM). These seeds originating from Wakwa and/or Yagoua experimental sites were assessed and compared in a split-plot design (4 × 5) × 3 between treatments (4) and varieties (5). The local DIR-95 variety had values close to those of Nerica varieties in all the parameters assessed. Protein contents ranged from 17.66% - 24.35%, and was higher than those reported in rice samples elsewhere. All the studied varieties were classified as high amylose rice, and therefore, their textures in cooked form should be less sticky and harder, which is convenient to the diet behavior of many consumers. The relative low Fe content in Nerica rice suggest that these varieties may be resistant to Fe accumulation in seeds. The P, N, Mg contents were found to be more elevated in seeds harvested from mycorrhiza or chemical fertilizer applied plants, with Nerica seeds variety FKR62-N as the best of all in nutrients mineral and nutritional compositions. These results confirm varietal and site influences on proximate and mineral contents in the studied rice varieties.
文摘ISFM (integrated soil fertility management) involving annual sequencing of dual-purpose early-maturing first crop of cowpeas with biomass incorporation before seeding second crop of early-maturing NERICA (New Rice for Africa) was evaluated to enhance rice productivity and soil-nitrogen. Five dual-purpose early-maturing cowpea cultivars and local cultivar (Katche) were seeded early in the wet season in five farmers' fields at Ouake (9046' N, 1°35′ E, highly degraded-savanna), Benin. After pod harvest, cowpea residues were minimally worked into the soil using minimum tillage with hand-hoe and seeded with early-maturing, resilient NERICA8 rice that received either 20 kg N/ha or zero-N. Cowpea grain yield averaged 0.1-0.3 Mg/ha, and mean aboveground cowpea biomass produced and recycled was 0.54-0.64 Mg/ha among best cultivars (IT97-568-11 and IT89KD-288). NERICA8 seeded after cowpea cv. IT97-568-11 and supplied with 20N gave the greatest grain yield of about 2.0 Mg/ha, accounting for 500% heavier grains than fallow-rice rotation with zero-N. Mineral-N dynamics monitored under NERICA8 in year 2 showed that previous IT97-568-11 plots had the highest mineral-N at tillering which persisted till panicle initiation stage. The adoption of an ISFM comprising annual cowpea-NERICA sequence by smallholder rice farmers could enhance productivity and improve N-supply in fragile savannas.
文摘The responses of five inter-specific lowland rice cultivars (NERICA-L-19, NERICA-L-20, NERICA-L-41, NERICA-L-42, and NERICA-L-60) and four improved Oryza sativa cultivars (FKR 19, BW 348-1, WITA 4, and SIPI 6923033) to levels of phosphorus and nitrogen fertilization were compared on a Typic Natrustalfat Kadawa in the Nigerian Sudan Savanna in 2006 and 2007 The responses of the NERICA-L eultivars to N and P fertilization were similar to the O. sativa cultivars. In a dry year (2007), the NERICA-L cultivars gave higher yields than O. sativa cultivars. Phosphorus level did not significantly affect crop physiology, yield, and yield components of all the cultivars. Pooled across cultivars, N and P levels, days to panicle initiation, mid-flowering and maturity were, respectively delayed by 17.0, 15.6 and 6.4 days in 2007 compared to 2006. NERICA-L-42 and NERICA-L-41 were the most stable, exhibiting the least difference in duration to maturity between the two years (3.5 and 4.4 days, respectively), and could therefore be more adapted to rain-fed environments prone to frequent droughts. Increasing N levels from 0 to 120 kg hal produced yield increments of 62.9 and 37.2% in 2006 and 2007, respectively. Cultivars FKR 19 and WITA 4 gave higher yields in 2006 (3940 and 3542 kg ha^-1, respectively), while in 2007, NERICA-L-42, NERICA-L^-19 and NERICA-L-20 ranked among the highest in grain yield (3935, 3807 and 3726 kg hal, respectively) and could be recommended to resource-poor farmers. a
文摘A two-year field experiment was conducted to evaluate the influence of nitrogen (0, 30, 60, and 120 kg N ha^-1) and phosphorus (0, 30, and 60 kg P2O5 ha^-1) application on grain yield and yield components of five New Rice for Africa (NERICA) cultivars, their parents, and a check on a degraded soil in the moist savanna of Nigeria. Nerica 14 recorded the highest grain yield of 1.3 mg halcompared to the other NERICA cultivars. It also produced significantly (P 〈 0.05) longer panicles (19.24 cm), higher sink capacity as determined by thousand-kernel weight (30.3 g), and a higher potential for partitioning photosynthates (45.15%) into grains than the other cultivars. N × P interaction effect on grain yield was significant (P 〈 0.05) with moderate P (60 kg P2O5 ha^1) and moderate N (60 kg N ha^-1) resulting in optimum grain yield (1.7 mg ha^-1). Thus, moderate N and P were recommended for the production of NERICA varieties in low-input smallholder upland rice production systems of the moist savanna of Nigeria.
文摘A two-year on-farm study was carried out at Eglime in the moist savanna (MS) and Ouake in the dry savanna (DS) of Benin to evaluate the contribution of inoculation of dual-purpose soybean varieties to grain yield of upland NERICA rice fertilized with low N level. In 2005, four dual-purpose, promiscuous soybean varieties (cv. TGx1440-IE; TG×1448-2E; TG×1019-2EB; and TG×1844-18E), and a popular improved variety (cv. Jupiter) were sown in 12 farmer fields with and without Bradyrhizobium japonicum inoculation. There was also land which was left fallow that acted as the control. In 2006, upland interspecific rice (NERICA 1) was sown in all the plots and supplied with 15 kg N haL. Dry matter yield, N accumulation, and net N-balance were significantly enhanced by over 40% with inoculation of cv. TG× 1844-18E than non-inoculation in the DS in comparison to other cultivars. There were no significant effects of inoculation of previous soybean cultivars on soybean grain yield and on the succeeding NERICA rice yield. Averaged over inoculation, previous cv. TG× 1019-2EB plots supplied with only 15 kg N hal gave the highest grain yield, more than twice the yield of control plots in the DS, possibly because of significant production of higher tillers, panicles and harvest index than the other cultivars; and it could be recommended for upland rice-based system for NERICA production.
文摘Eritrean farmers can cultivate rice by harvesting runoff from >82% available non-agricultural land in agricultural watersheds for crop use and reducing percolation through optimization of tillage. Experiments were conducted with NERICA rice, N11, to optimize irrigation requirements and puddling and compaction to reduce percolation. Experimental field was adjacent to Anseba River at downstream end of the watershed and a pond on the upstream to intercept runoff. Irrigation treatments were runoff farming with maximum runoff application depth of 10 mm (I<sub>1</sub>), and 50 mm irrigation two (I<sub>2</sub>), five (I<sub>3</sub>), and seven (I<sub>4</sub>) days after disappearance of ponded water in main plots and puddling by one (T<sub>1</sub>), two (T<sub>2</sub>) and three (T<sub>3</sub>) passes of puddler and compaction by three (T<sub>4</sub>), four (T<sub>5</sub>) and five (T<sub>6</sub>) passes of 600 kg roller in sub plots in 3 replications. Soil profile was loam in the surface 0.45 m and coarse sandy loam below forming porous belt. Soil submergence was difficult to maintain, but water table was developed in soil profile due to inflow of seepage from the river and pond. Depth to the water table was within 1.5 ± 0.1 m for >2 months and receded down to 1.7 m by crop maturity. Soil wetness was near field capacity around 0.7 m depth and increased below due to natural sub-irrigation from the water table. Rice roots penetrated 0.8 m in the puddled plots and 0.7 m in the compacted plots. Residual soil moisture of 135 - 146 mm·m<sup>-1</sup> after rice harvesting provides opportunity for planting rapeseed mustered following rice. Puddling was superior to compaction in loam soil. Puddling twice and irrigation 50 mm 7 days after ponded water vanished from surface was sufficient for optimum rice grain yield of 4346 kg·ha<sup>-1</sup> and straw yield of 4458 kg·ha<sup>-1</sup>. Optimum puddling and irrigation schedules reduced crop duration by 6 days without significantly affecting yield. Production function showed that rice grain yield of 4789 kg ha<sup>-1</sup> could be obtained by 1009 mm applied water through rainfall and irrigation.
文摘Sustainable rice production in Sierra Leone faces serious constraints due to soil acidity, low cation exchange capacity, low nutrient contents accelerated mineralization of soil organic matter and soil loss by erosion (particularly on the uplands). One possible approach to addressing the soil constraints to rice production both on uplands and lowlands of Sierra Leone is the recycling of rice residues through biochar production and application to soils. A pot experiment was conducted to investigate the effects of application of biochar from rice residues on (i) soil physicochemical properties and (ii) the early growth characteristics of two rice varieties, NERICA L19 and ROK3. The experiment was arranged in a completely randomized design (CRD) with two biochar levels (0 and 15 g/kg soil) and two rice varieties in three replications. For the biochar treated soils (+biochar), 75 g rice straw biochar was applied to 5 kg air-dry soil (15 kg biochar/kg soil), mixed thoroughly and placed into perforated black polythene bags. Seeds of two rice varieties, NERICA L19 and ROK3 were planted on the treated and untreated soils for eight weeks. Application of biochar improved available phosphorus, exchangeable cations and cation exchange capacity in biochar treated soils compared to the control soil without biochar. Plant height, tiller number, and dry biomass weight of both rice varieties grown in soils amended with rice straw biochar were significantly higher than those on untreated soils. The most remarkable increase in plant growth characteristics as a result of biochar addition to soil was reflected in the biomass yield and tiller numbers. Dry shoot biomass for ROK3 rice variety varied significantly from a mean of 3.5 g (control) to 26.2 g (+biochar) while tiller numbers significantly varied from 10 (control) to 29.6 (+biochar). Similarly, for NERICA L19 rice variety, dry shoot biomass increased significantly from 4.5 g (control) to 22.7 g (+biochar) while tiller numbers increased significantly from a mean of 12.3 (control) to 30 (+biochar). Thus converting rice residues to biochar and applying to soil holds promise for improving rice production in Sierra Leone.
文摘Rice is not cultivated in Eritrea because of its high water requirements and arid to semiarid conditions. However, most agricultural watersheds in Eritrea are associated with >80% non-agricultural lands, which produce significant runoff that can be diverted for use by rice crop. Experiments were conducted at Hamelmalo Agricultural College, Eritrea, using four NERICA rice varieties viz. N1, N4, N10 and N11 under rainfed (Io) and limited supplementary irrigations (I) in 3 replications. Results showed that plants were taller under limited irrigations than rainfed. Among the 4 varieties, N11 was most affected by water stress in which plant height was 0.72 m under rainfed and 0.89 m under limited irrigations. Effective tillers were highest (6) in N11 under limited irrigations and lowest (2) in N10 under rainfed. Panicles were shorter (0.20 m) in N10 and longer (0.23 - 0.24 m) in N1 and N11. Irrigations delayed maturity by 6 - 15 days. Water use by N11 was higher both under limited irrigations (987 mm) and rainfed (477 mm) and lower by N10 under rainfed (457 mm). Root growth in all the varieties was better under irrigations (I) than rainfed (Io). Roots were limited to 0.7 m depth under rainfed (Io) but grew down to 0.8 m in N1, N4 and N11 under limited irrigations (I). Roots in N10 were limited to 0.5 m depth under Io and 0.7 m under I. More than 63% roots in N10 were in 0 - 0.1 m layer under rainfed as against less than 55% under limited irrigations. In lower layers, roots under Io were more in N4 than others, which is a beneficial trait for better performance under semiarid environments. Roots in N11 were better and uniformly distributed in lower layers under irrigated conditions. Rooting patterns and grain yields showed that N11 was most responsive to irrigations but susceptible to water stress and N4 was best under rainfed followed by N10. N4 was next to N11 under irrigated conditions.
文摘Rainfed Aus rice is a popular conventional rice cultivation technique that through appropriate variety selection can accelerate the benefits of the farmer. On this context, an experiment was carried out at the research field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur1706 from April to August in 2014 to evaluate yield performance of some Aus rice varieties under rainfed condition. The experiment was laid out in a split plot design with three replications. The experiment consisted of two sets of treatments: water regime as irrigated (irrigation when necessary) and rainfed (dependent on rainfall) in the main plot and 15 varieties into sub-plots. It was revealed that yield and yield contributing characters were significantly influenced by water regime, variety and their interaction. The traits like number of effective tillers and non-effective tillers·hill-1, number of filled grains and unfilled grains panicle-1, panicle length, test weight, grain yield and harvest index were higher in irrigated crops compared to rainfed. Considering the performance of yield, the highest grain yield recorded in BRRI dhan27 (irrigated-2.47 t·ha-1 and rainfed-2.26 t·ha-1) followed by BRRI dhan55 (irrigated-1.95 t·ha-1 and rainfed-1.88 t·ha-1), BRRI dhan48 and BRRI dhan43 under both irrigated and rainfed treatment. BRRI dhan27 ranked the top under both irrigated and rainfed conditions, however the relative yield was maximum in BRRI dhan55 (reduction was only 3.59%) followed by Nerica10. Hence, considering the yield stability and absolute yield performance, BRRI dhan27 may be considered favorably cultivable for Aus season in Bangladesh followed by BRRI dhan55, BRRI dhan48 and BRRI dhan43.