Consumption of nutrient rich foods such as beans and peas is recommended because these foods provide key nutrients and relatively little energy. Many consumers are unfamiliar with dried beans or do not have the time t...Consumption of nutrient rich foods such as beans and peas is recommended because these foods provide key nutrients and relatively little energy. Many consumers are unfamiliar with dried beans or do not have the time to prepare them. The purpose of this study was to compare nutrient density and nutrient-to-cost among dried cooked, canned (liquid and solids), and canned/drained black, garbanzo, kidney, lima, pinto, white beans, and black-eyed peas. Prices were obtained from 60 grocery stores in January 2009. Nutrient content per 100 g was calculated using the U.S. Department of Agriculture Nutrient Database for Standard Reference, Release 22, and Nutrition Data System for Research (for canned/drained). Nutrient density scores were estimated using the Nutrient Rich Food Index 9.3 (NRF9.3). Nutrient-to-cost ratio (NTCR) was computed as the NRF 9.3 score (per 100 kcal) divided by the cost per half-cup servings per package (12) or per can (3.5). Compared to canned beans, dried cooked beans were significantly more energy dense, contained more protein, fiber, iron, potassium and magnesium;and less sodium than canned beans (p < 0.05 for all). Canned/drained beans contained more sodium than cooked beans (p < 0.05). NRF9.3 scores were 7.3, 2.8, and 4.8 for cooked, canned, and canned/drained beans, respectively. NTCR for cooked, canned, and canned/drained beans was 63.4, 8.9, and 15.2, respectively. Results highlight the benefits of choosing dried beans and also illustrate that canned beans, when drained, provide a healthy alternative. Beans, regardless of type/form, are a nutrient rich food and should be encouraged as part of an overall healthy diet.展开更多
Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer ...Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer rates on rain use efficiency (RUE), harvest index, agronomic use efficiency of phosphorous (AEP) and potassium (AEK), and value cost ratio (VCR) were evaluated. The applied diagnostic PK fertilizer rates significantly improved soybean grain yields, harvest index, rainwater use efficiency, AEP, AEK and returns to fertilizer use expressed as value cost ratio (VCR). However, the results differed significantly展开更多
This study was executed to offer the basis for optimized profit from fertilizer use for sorghum yield and to determine robust crop nutrient response function and economic rate for the production of sorghum at Miesso C...This study was executed to offer the basis for optimized profit from fertilizer use for sorghum yield and to determine robust crop nutrient response function and economic rate for the production of sorghum at Miesso Central Rift Valley of Ethiopia. Trails were conducted at six experimental sites, sorghum yield response to N and P fertilizers application and economically optimum rates of nitrogen (EONR) and phosphorus (EOPR) were evaluated on a vertisols within the semi-arid Miesso districts west Hararge zone of Oromia region. The nutrient rates in 2014 cropping season four levels of Nitrogen (N) alone, these levels with 20 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> Phosphorus (P) and without N, 69 kg<span style="white-space:nowrap;">·</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup> N with three levels of P treatments including the zero control were evaluated. In 2015, cropping season similar rates of N alone, the same rate N with 20 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> P, 92 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> N with three rates of P including the zero control were evaluated. The treatments were arranged in a randomized complete block with three replications in factorial design. Nutrient responses of sorghum were determined using asymptotic quadratic plateau functions. The significantly highest nitrogen rate was 46 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> alone in 2014 season, which gave grain yield of 2.56 Mg<span style="white-space:nowrap;">·ha<sup>−1</sup></span><sup> </sup>with a maximum yield advantage of 43%. P rates in both seasons and combined (sites + seasons) were not significantly influenced sorghum yield. Nitrogen agronomic and partial factor productivity peaked at 23 kg N <span style="white-space:nowrap;">ha<sup>−1</sup></span> but declined with increasing N rate. The EONR combined (sites + seasons) were 37, 45, 52 and 60 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span><sup> </sup>and for the profit to cost ratio (PCR) were 2.43, 3.65, 4.86 and 5.79 at difference cost to grain price ratios (CP) = 3.6, 2.3, 1.6 and 1.2 respectively at Miesso Ethiopia. Nitrogen application had economically profitable than P. The study concluded that the application of N at 37 or 60 kg N <span style="white-space:nowrap;">ha<sup>−1</sup></span> to sorghum production could be economically profitable for those economically constrained farmers or economically not constrained farmers. Validation should be farther conducted on farmers’ fields for refining the results obtained.展开更多
Models predicting optimal levels of plant defense against herbivores typically include two assumptions: 1) defense is both beneficial and costly;and 2) the relationship between costs and benefits of a defense is consi...Models predicting optimal levels of plant defense against herbivores typically include two assumptions: 1) defense is both beneficial and costly;and 2) the relationship between costs and benefits of a defense is consistent across environments. However, the expression of costs and benefits of defense may be environmentally dependent. We examined lines of Brassica rapa, previously divergently selected for the defensive trait foliar glucosinolate content. In one set of experiments (Experiment #1), plants were grown in herbivore-free and herbivore-present environments to investigate the costs and benefits of this defense. In a second set of experiments (Experiment #2), plants were grown at two nutrient levels and two temperatures to examine the environmental context of costs of defense. In Experiment #1, increased levels of damage resulted in decreased flower production and plants from high glucosinolate lines received less damage than those from low glucosinolate lines, suggesting a benefit of this defense. In this experiment no cost of defense was detected. In Experiment #2, nutrients had a significant positive effect on flower production at 23°C, but not at 32°C. No significant effects of glucosinolate line nor interaction between nutrient environment and glucosinolate line were detected at 23°C, suggesting that no cost of defense occurred at this lower temperature. Similarly, no significant nutrient environment by glucosenolate line interaction was detected at 32°C. However, a significant effect of glucosinolate line was observed suggesting that at 32°C costs were incurred, but nutrient environment had no mitigating effect. While results from Experiment #1 suggested that defense was beneficial, but not costly, results from Experiment #2 suggested that costs of defense were temperature dependent. For species occupying broad geographic ranges, these findings of temperature-dependent costs are especially insightful with regard to the evolution of defense because differing geographic populations are likely to experience differing temperature environments.展开更多
【目的】农户经营是我国农业的主体,肥料资源的不合理应用是限制作物生产的重要因子。本研究旨在评估主产区农户粮食生产的减肥潜力及经济环境效益。【方法】2018年对陕西省各县(市、区)的主要农作物生产情况进行问卷调查,以三大粮食作...【目的】农户经营是我国农业的主体,肥料资源的不合理应用是限制作物生产的重要因子。本研究旨在评估主产区农户粮食生产的减肥潜力及经济环境效益。【方法】2018年对陕西省各县(市、区)的主要农作物生产情况进行问卷调查,以三大粮食作物为研究对象,基于产量水平评价农户的施肥现状、减肥潜力、环境代价和经济效益。【结果】农户作物产量存在显著差异,小麦平均产量为4 573 kg·hm^-2,高低产量相差2 619 kg·hm^-2;玉米平均产量为7 319 kg·hm^-2,高低产量相差5 388 kg·hm^-2;水稻平均产量为8 340 kg·hm^-2,高低产量相差2 893kg·hm^-2。小麦的氮磷钾肥用量分别为177 kg N·hm^-2、102 kg P2O5·hm^-2和37 kg K2O·hm^-2;玉米分别为247 kg N·hm^-2、103 kg P2O5·hm^-2和47 kg K2O·hm^-2;水稻分别为186 kg N·hm^-2、88 kg P2O5·hm^-2和64 kg K2O·hm^-2。3种作物产量与施肥量无显著相关。氮磷肥普遍过量施用、钾肥过量与不足并存,低产农户过量施肥问题严重。对于氮磷钾肥的减施潜力,小麦分别为41%、59%和59%;玉米分别为55%、73%和66%;水稻分别为38%、64%和58%。施用的肥料形态均表现氮以单质肥为主、复合肥为辅;磷钾以复合肥为主;有机肥养分供应量很低。肥料结构均表现为重基施轻追施,氮以基施为主、追施为辅;磷钾肥鲜有追施。生产1.0 t小麦、玉米和水稻的活性氮损失量分别为6.9、3.8和3.3 kg,低产组的活性氮损失强度比高产组分别高52%、85%和74%,降低损失的潜力分别介于16%-33%、31%-50%和4%-38%。小麦、玉米和水稻生产的经济效益分别为4 468、9 091和20 020元/hm2,高产组比低产组分别高459%、128%和52%;减肥增效后总效益分别为4 919、9 905和20 543元/hm2,高产组比低产组分别高290%、106%和48%。【结论】基于产量水平深入剖析了陕西省农户的生产行为,低中产组为化肥减量和收益提升的重点。农户氮磷钾肥减施潜力分别为45%、65%和61%;小麦、玉米和水稻因化肥减施而降低活性氮损失的潜力分别为26%、45%和18%;提高环境经济效益的潜力分别为10%、9%和3%。展开更多
文摘Consumption of nutrient rich foods such as beans and peas is recommended because these foods provide key nutrients and relatively little energy. Many consumers are unfamiliar with dried beans or do not have the time to prepare them. The purpose of this study was to compare nutrient density and nutrient-to-cost among dried cooked, canned (liquid and solids), and canned/drained black, garbanzo, kidney, lima, pinto, white beans, and black-eyed peas. Prices were obtained from 60 grocery stores in January 2009. Nutrient content per 100 g was calculated using the U.S. Department of Agriculture Nutrient Database for Standard Reference, Release 22, and Nutrition Data System for Research (for canned/drained). Nutrient density scores were estimated using the Nutrient Rich Food Index 9.3 (NRF9.3). Nutrient-to-cost ratio (NTCR) was computed as the NRF 9.3 score (per 100 kcal) divided by the cost per half-cup servings per package (12) or per can (3.5). Compared to canned beans, dried cooked beans were significantly more energy dense, contained more protein, fiber, iron, potassium and magnesium;and less sodium than canned beans (p < 0.05 for all). Canned/drained beans contained more sodium than cooked beans (p < 0.05). NRF9.3 scores were 7.3, 2.8, and 4.8 for cooked, canned, and canned/drained beans, respectively. NTCR for cooked, canned, and canned/drained beans was 63.4, 8.9, and 15.2, respectively. Results highlight the benefits of choosing dried beans and also illustrate that canned beans, when drained, provide a healthy alternative. Beans, regardless of type/form, are a nutrient rich food and should be encouraged as part of an overall healthy diet.
文摘Field trials were conducted to determine the economically optimum fertilizer rates for soybean production and for optimizing net profits in Dedza, Lilongwe and Salima Districts of Malawi. The effects of PK fertilizer rates on rain use efficiency (RUE), harvest index, agronomic use efficiency of phosphorous (AEP) and potassium (AEK), and value cost ratio (VCR) were evaluated. The applied diagnostic PK fertilizer rates significantly improved soybean grain yields, harvest index, rainwater use efficiency, AEP, AEK and returns to fertilizer use expressed as value cost ratio (VCR). However, the results differed significantly
文摘This study was executed to offer the basis for optimized profit from fertilizer use for sorghum yield and to determine robust crop nutrient response function and economic rate for the production of sorghum at Miesso Central Rift Valley of Ethiopia. Trails were conducted at six experimental sites, sorghum yield response to N and P fertilizers application and economically optimum rates of nitrogen (EONR) and phosphorus (EOPR) were evaluated on a vertisols within the semi-arid Miesso districts west Hararge zone of Oromia region. The nutrient rates in 2014 cropping season four levels of Nitrogen (N) alone, these levels with 20 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> Phosphorus (P) and without N, 69 kg<span style="white-space:nowrap;">·</span>ha<sup><span style="white-space:nowrap;">−</span>1</sup> N with three levels of P treatments including the zero control were evaluated. In 2015, cropping season similar rates of N alone, the same rate N with 20 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> P, 92 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> N with three rates of P including the zero control were evaluated. The treatments were arranged in a randomized complete block with three replications in factorial design. Nutrient responses of sorghum were determined using asymptotic quadratic plateau functions. The significantly highest nitrogen rate was 46 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span> alone in 2014 season, which gave grain yield of 2.56 Mg<span style="white-space:nowrap;">·ha<sup>−1</sup></span><sup> </sup>with a maximum yield advantage of 43%. P rates in both seasons and combined (sites + seasons) were not significantly influenced sorghum yield. Nitrogen agronomic and partial factor productivity peaked at 23 kg N <span style="white-space:nowrap;">ha<sup>−1</sup></span> but declined with increasing N rate. The EONR combined (sites + seasons) were 37, 45, 52 and 60 <span style="white-space:nowrap;">kg·ha<sup>−1</sup></span><sup> </sup>and for the profit to cost ratio (PCR) were 2.43, 3.65, 4.86 and 5.79 at difference cost to grain price ratios (CP) = 3.6, 2.3, 1.6 and 1.2 respectively at Miesso Ethiopia. Nitrogen application had economically profitable than P. The study concluded that the application of N at 37 or 60 kg N <span style="white-space:nowrap;">ha<sup>−1</sup></span> to sorghum production could be economically profitable for those economically constrained farmers or economically not constrained farmers. Validation should be farther conducted on farmers’ fields for refining the results obtained.
文摘Models predicting optimal levels of plant defense against herbivores typically include two assumptions: 1) defense is both beneficial and costly;and 2) the relationship between costs and benefits of a defense is consistent across environments. However, the expression of costs and benefits of defense may be environmentally dependent. We examined lines of Brassica rapa, previously divergently selected for the defensive trait foliar glucosinolate content. In one set of experiments (Experiment #1), plants were grown in herbivore-free and herbivore-present environments to investigate the costs and benefits of this defense. In a second set of experiments (Experiment #2), plants were grown at two nutrient levels and two temperatures to examine the environmental context of costs of defense. In Experiment #1, increased levels of damage resulted in decreased flower production and plants from high glucosinolate lines received less damage than those from low glucosinolate lines, suggesting a benefit of this defense. In this experiment no cost of defense was detected. In Experiment #2, nutrients had a significant positive effect on flower production at 23°C, but not at 32°C. No significant effects of glucosinolate line nor interaction between nutrient environment and glucosinolate line were detected at 23°C, suggesting that no cost of defense occurred at this lower temperature. Similarly, no significant nutrient environment by glucosenolate line interaction was detected at 32°C. However, a significant effect of glucosinolate line was observed suggesting that at 32°C costs were incurred, but nutrient environment had no mitigating effect. While results from Experiment #1 suggested that defense was beneficial, but not costly, results from Experiment #2 suggested that costs of defense were temperature dependent. For species occupying broad geographic ranges, these findings of temperature-dependent costs are especially insightful with regard to the evolution of defense because differing geographic populations are likely to experience differing temperature environments.
文摘【目的】农户经营是我国农业的主体,肥料资源的不合理应用是限制作物生产的重要因子。本研究旨在评估主产区农户粮食生产的减肥潜力及经济环境效益。【方法】2018年对陕西省各县(市、区)的主要农作物生产情况进行问卷调查,以三大粮食作物为研究对象,基于产量水平评价农户的施肥现状、减肥潜力、环境代价和经济效益。【结果】农户作物产量存在显著差异,小麦平均产量为4 573 kg·hm^-2,高低产量相差2 619 kg·hm^-2;玉米平均产量为7 319 kg·hm^-2,高低产量相差5 388 kg·hm^-2;水稻平均产量为8 340 kg·hm^-2,高低产量相差2 893kg·hm^-2。小麦的氮磷钾肥用量分别为177 kg N·hm^-2、102 kg P2O5·hm^-2和37 kg K2O·hm^-2;玉米分别为247 kg N·hm^-2、103 kg P2O5·hm^-2和47 kg K2O·hm^-2;水稻分别为186 kg N·hm^-2、88 kg P2O5·hm^-2和64 kg K2O·hm^-2。3种作物产量与施肥量无显著相关。氮磷肥普遍过量施用、钾肥过量与不足并存,低产农户过量施肥问题严重。对于氮磷钾肥的减施潜力,小麦分别为41%、59%和59%;玉米分别为55%、73%和66%;水稻分别为38%、64%和58%。施用的肥料形态均表现氮以单质肥为主、复合肥为辅;磷钾以复合肥为主;有机肥养分供应量很低。肥料结构均表现为重基施轻追施,氮以基施为主、追施为辅;磷钾肥鲜有追施。生产1.0 t小麦、玉米和水稻的活性氮损失量分别为6.9、3.8和3.3 kg,低产组的活性氮损失强度比高产组分别高52%、85%和74%,降低损失的潜力分别介于16%-33%、31%-50%和4%-38%。小麦、玉米和水稻生产的经济效益分别为4 468、9 091和20 020元/hm2,高产组比低产组分别高459%、128%和52%;减肥增效后总效益分别为4 919、9 905和20 543元/hm2,高产组比低产组分别高290%、106%和48%。【结论】基于产量水平深入剖析了陕西省农户的生产行为,低中产组为化肥减量和收益提升的重点。农户氮磷钾肥减施潜力分别为45%、65%和61%;小麦、玉米和水稻因化肥减施而降低活性氮损失的潜力分别为26%、45%和18%;提高环境经济效益的潜力分别为10%、9%和3%。
