Variability on Yield,Nutritional Status,Soil Fertility,and Potassium-Use Efficiency by Soybean Cultivar in Acidic Soil

The use of cultivar with nutrient-use efficiency is an important strategy in the management of plant nutritional status, particularly potassium (K), because its high demand and the progressive impoverishment caused by the use of inadequate amounts cause frequent deficiency symptoms observed in soybean [Glycine max (L.) Merrill] crops. This study was conducted in greenhouse conditions in a completely randomized design with four replicates in an Typic Quartzipsamment soil aimed to assess the effect of applying two rates of K (50 and 200 mg kg^?1) on growth, shoot dry weight yield (SDWY) and seed yield (SY), nutritional status, yield components, and efficiency of K use in eleven cultivars of different characteristics and growth habits. The SDWY, SY, number of seeds per pod, number of pods, and estimated 100-seed weight showed significant interaction between cultivar and the K rates, with greater values at the rate 200 mg K kg^?1. Similarly, the concentration of nitrogen (N), phosphorus (P), K, calcium (Ca), magnesium (Mg), sulfur (S), boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) in leaves and grains varied according to the K rates and in the cultivar. The most K-use efficient cultivars were BMX Magna RR, BRS 232, BRS 284, BRS 294RR, NA 5909RR, and Vmax RR, whereas FTS Campo Mourão RR was inefficient. Regarding response to fertilization, the cultivars Vmax RR, BMX Magna RR, NA 5909RR, BRS 284, and BRS 294RR were found to be efficient and responsive, whereas the cultivar FTS Campo Mourão RR, BRS 232, BMX Potência RR, BRS 295RR, TMG 1066RR, and TMG 1067RR are inefficient and responsive to K application in the soil.     

Sulfur Use Efficiency in Soybean Cultivars Adapted to Tropical and Subtropical Conditions

Sulfur (S) is an essential nutrient in crop plants and one of the components of amino acids (AAs) and proteins. Studies about sulfur efficiency on soybean cultivars [Glycine max (L) Merril] adapted to the tropical and subtropical conditions are still incipient. In Brazil, one experiment under greenhouse conditions evaluated the S-efficiency from eight soybean cultivars. The plants cultivated in a Typic Quartzipsamment received two S rates (0 and 80 mg kg^?1). The grain yield (GY), shoot dry weight (SDW), and the relative yield (RY) had influence from the S rates. The cultivars BRS 295RR and BRS 360RR were the most efficient in using the S application. The number of pods per plant (NPP), photosynthetic rate (A), nitrate reductase (N-NO₂^?), and chlorophyll significantly increased with de 80 mg kg^?1 of S. By contrast, the internal concentration of carbon dioxide (CO₂) (Ci) was reduced. Similarly, there were increases in the concentration of nitrogen (N), phosphorus (P), magnesium (Mg), and N:S ratio in the leaves and grain, but the K increased only in the leaves. Comparing the cultivars, only the N concentration in the leaves and the Mg in the grain had non-significant differences.     

Phosphorus,Potassium and Sulfur Interactions in Soybean Plants on a Typic Hapludox

Soybean (Glycine max (L.) Merril) has the largest acreage in Brazil where nutrients are provided to crops by formulated fertilizers, which is the most usual method. Under tropical and subtropical conditions, most of the nutrients required by soybean crops are phosphorus (P) and potassium (K), while sulfur (S) is applied in smaller amounts. The P, K, and S interactions under greenhouse conditions using completely randomized blocks in a factorial 3 × 3 × 3 arrangement were evaluated. The treatments were as follows: three P rates (0, 75, and 150 mg P kg^?1); three K rates (0, 150, and 300 mg K kg^?1); and three S rates (0, 50, and 100 mg S kg^?1). The P, K, and S application had a significant influence on the shoot dry weight (SDW) and number of pods per pot (NPP) in contrast with the increase in grain yield (GY) that had positive relationship with K and S rates. These results indicated that both nutrients were the most limiting to GY. In soil and leaves, only the P, K, and S concentrations were modified by the treatments (P, K, and S), but in the grains there was synergism of P rates with Mg concentration unlike K rates with Ca concentration. Physiological components as photosynthetic rate, intrinsic efficiency of water use, and chlorophyll had influence from P and K rates.     

Influence of Lime and Gypsum on Yield and Yield Components of Soybean and Changes in Soil Chemical Properties

Soybean is one of the most important legume crops in the world. Two greenhouse experiments were conducted to determine the influence of liming and gypsum application on yield and yield components of soybean and changes in soil chemical properties of an Oxisol. Lime rates used were 0, 0.71, 1.42, 2.14, 2.85, and 4.28 g kg^?1 soil. Gypsum rates applied were 0, 0.28, 0.57, 1.14, 1.71, and 2.28 g kg^?1 soil. Lime as well as gypsum significantly increased grain yield in a quadratic fashion. Maximum grain yield was achieved with the application of 1.57 g lime per kg soil, whereas the gypsum requirement for maximum grain yield was 1.43 g per kg of soil. Lime significantly improved soil pH, exchangeable soil calcium (Ca) and magnesium (Mg) contents, base saturation, and effective cation exchange capacity (ECEC). However, lime application significantly decreased total acidity [hydrogen (H) + aluminum (Al)], zinc (Zn), and iron (Fe) contents of the soil. The decrease in these soil properties was associated with increase in soil pH. Gypsum application significantly increased exchangeable soil Ca, base saturation, and ECEC. However, gypsum did not change pH and total acidity (H + Al) significantly. Adequate soil acidity indices established for maximum grain yield with the application of lime were pH 5.5, Ca 1.8 cmol_c kg^?1, Mg 0.66 cmol_c kg^?1, base saturation 53%, Ca saturation 35%, and Mg saturation 13%. Soybean plants tolerated acidity (H + Al) up to 2.26 cmol_c kg^?1 soil. In the case of gypsum, maximum grain yield was obtained at exchangeable Ca content of 2.12 cmol_c kg^?1, base saturation of 56%, and Ca saturation of 41%.     

Lime and Cattle Manure in Soil Fertility and Soybean Grain Yield Cultivated in Tropical Soil

Most tropical soils have high acidity and low natural fertility. The appropriate application of lime and cattle manure corrects acidity, improves physical and biological properties, increases soil fertility, and reduces the use of chemical and/or synthetic fertilizers by crops, such as soybean, the main agricultural export product of Brazil. This study aimed to assess the effects of the combination of the application of dolomite limestone (0, 5, and 10 Mg ha^?1) and cattle manure (0, 40, and 80 Mg ha^?1) on grain yield and the chemical properties of an Oxisol (Red Latosol) cultivated with soybean for two consecutive years. The maximum grain yield was obtained with the application of 10 Mg ha^?1 of lime and 80 Mg ha^?1 of cattle manure. Liming significantly increased pH index, the concentrations of calcium (Ca²⁺) and exchangeable magnesium (Mg²⁺), and cation exchange capacity (CEC) of soil and reduced potential acidity (H⁺ + Al³⁺), while the application of cattle manure increased pH level; the concentrations of potassium (K⁺), Ca²⁺, and exchangeable Mg²⁺; and CEC of the soil. During the 2 years of assessment, the greatest grain yields were obtained with saturation of K⁺, Ca²⁺, and Mg²⁺ in CEC at the 4.4, 40.4, and 17.5 levels, respectively. The results indicated that the ratios of soil exchangeable Ca/Mg, Ca/K, K/Mg, and K/(Ca+Mg) can be modified to increase the yield of soybean grains.     

Soybean response to copper applied to two soils with different levels of organic matter and clay

Abstract

Increasing the amount of soil organic matter (OM) alters the availability of copper (Cu) for plants under tropical and subtropical conditions. With the aim of evaluating the effects of the OM/Cu interaction on the soybean crop, a trial was conducted with a fully randomized 2?×?5 factorial design and four replicates. The treatments consisted of five Cu rates (0, 1, 2, 4 and 8?mg kg^?1) and two soil types: Typic Oxisol and Typic Ultisol. The soybean responded to fertilization with Cu, producing the highest estimated grain yield at a rate of 4.1?mg kg^?1. Similarly were also observed for shoot dry weight, number of pods and root length. The soil chemical properties and nutrient levels in the leaves and grain were influenced only by the soil type, whereas physiological components were affected in terms of photosynthetic rate and intercellular CO₂ concentration.     

Yield and Yield Components and Phosphorus Use Efficiency of Lowland Rice Genotypes

Phosphorus deficiency is main constraints for lowland rice production in various rice producing regions of the world. A greenhouse experiment was conducted using lowland (Inceptisol) soil with the objective to determine response of seven lowland rice (Oryza sativa L.) genotypes to phosphorus fertilization and to evaluate their phosphorus (P) use efficiency. Phosphorus treatments included control (0 mg P kg^?1) and 200 mg P kg^?1 of soil. Plant height and shoot dry weight were significantly (P < 0.001) influenced by P treatments. Phosphorus X genotypes interaction was significant for shoot dry weight, indicating different response of genotypes under two P levels. At low P level, none of the genotypes produced grain yield, indicating original P level in the soil was too low for lowland rice yield. However, genotypes differed significantly in grain yield at high P level. Panicle number, panicle length, and thousand grains weight had a significant quadratic association with grain yield. However, spikelet sterility had a significant linear negative association with grain yield. The P use efficiency expressed as agronomic efficiency (AE), physiological efficiency (PE), agro-physiological efficiency (AP), apparent recovery efficiency (ARE), and utilization (UE) were significantly different among genotypes. These efficiencies were having significantly positive association with grain yield, with exception to ARE, indicating improving grain yield with improved P use efficiencies in rice.     

Effect of sulfur source and rates on yield and yield components of soybean in subtropical soils

Abstract

The supply of sulfur (S) fertilizers, such as phosphogypsum, to new agricultural frontiers has been hindered by the high cost of freight. However, this problem could be resolved by utilizing deposits of rock in the affected regions. Accordingly, a greenhouse study was designed to evaluate the effect of S source and rate on soybean yield. Five S rates (0, 50, 100, and 200?mg kg^?1) and five S sources (S-phosphogypsum, S-Niquelândia rock, S-Araripina rock, S-Grajaú rock, and S-Sulfurgran [90% S0?+?10% bentonite]) were applied to soybean grown in two soil types (Typic Ultisol and Typic Oxisol), which differ in clay content. Regardless of soil type, the application of P-phosphogypsum resulted in a higher grain yield. However, application of the other S sources also improved grain yield as well as total dry weight; S application, in general, improved soybean yield components (number of grains per pod, number of pods per pot, and weight of pods per pot), photosynthetic rate, chlorophyll content, and the S levels of leaves and grains as well as the available sulfate (SO₄^2-) levels in the soil. Therefore, for soybean grown in Typic Ultisol and Typic Oxisol, different S sources effectively improve a variety of variables that ultimately improve grain yield.     

Efficiency of Magnesium Use by Common Bean Varieties Regarding Yield,Physiological Components,and Nutritional Status of Plants

The magnesium (Mg) use efficiency in the selection of common bean (Phaseolus vulgaris L.) varieties may contribute to increased nutritional status and grain yield. Therefore, the present study aimed to assess common bean varieties following the application of Mg regarding productivity (yield), soil fertility, physiological components, and nutritional status. The experiment was conducted in a completely randomized design in a 5 × 2 factorial scheme with three replicates. Five common bean varieties [BRS Estilo, IPR Tangará, IPR Campos Gerais (CG), IAPAR 81, and BRS Ametista] supplemented with two Mg concentrations [low (0 mg kg^?1) and high (100 mg kg^?1)] using magnesium chloride (MgCl₂) as a source in an Ustoxix Quatzipsamment were assessed. The yield of shoot dry weight (SDW) and grains varied significantly between varieties and Mg rates. The high Mg concentration has negatively affected the yield of SDW and grains of variety IPR Tangará, and the opposite was observed for the other varieties. The physiological components associated with photosynthesis are directly related to the yield of SDW and grains. The concentrations of phosphorus (P), calcium (Ca), sulfur (S), and boron (B) in leaves and of S, B, iron (Fe), and manganese (Mn) in grains differed among the varieties and interactions of rates and varieties for B, indicating the presence of genetic factors in nutrient uptake.     

Interaction of Glyphosate with Zinc for the Yield,Photosynthesis, Soil Fertility and Nutritional Status of Soybean

Application of glyphosate herbicide in genetically modified (GM) soybean [Glycine max (L.) Merrill] in soils with low zinc (Zn) concentration may interfere in the uptake of this and other nutrients, with negative impact on productivity. Thus, an experiment was conducted in greenhouse conditions on Ustoxix Quatzipsamment soil to investigate the effects of the interaction of glyphosate with Zn for the yield, photosynthesis, soil fertility and nutritional status of soybean. The treatments consisted of two soybean varieties [BRS 133 (conventional—NGM) and its essentially derived transgenic line BRS 245RR (GM) with and without glyphosate application] and five Zn rates (0, 5, 10, 20 and 40 mg kg^?1, source zinc sulfate (ZnSO₄)), with four replicates. Except for the copper (Cu) and iron (Fe) concentrations, the introduction of the herbicide-resistant gene is the predominant factor reducing nutrient uptake, photosynthetic (A) rate, stomatal conductance (Gs), leaf chlorophyll and ureide concentrations. The administration of Zn rates lowered the leaf phosphorus (P) concentration, and there was significant increase in Zn concentration in the soil and in the plant. Except for the 20 mg kg^?1 of Zn rate, the use of the herbicide did not affect the shoot dry weight (SDW) and seed yield, and on average, the maximum seed yield was obtained with Zn concentrations of 26.4 and 18.7 mg kg^?1 extracted by Mehlich 1 and diethylenetriaminepentaacetic acid-triethanolamine (DTPA-TEA), respectively.     

Effect of Glyphosate and Zinc Application on Yield,Soil Fertility,Yield Components,and Nutritional Status of Soybean

Glyphosate is a widely used nonselective herbicide for the control of agricultural weeds. It is being increasingly used in glyphosate resistant genetically modified plants. However, there are few studies on its effects on the nutritional status of soybean, particularly on the uptake of zinc (Zn). Two experiments were conducted under field conditions in a Typic Quartzipsamment and an Orthic Ferralsol to investigate the effect of glyphosate application × Zn interaction on soil fertility, yield components, seed yield (SY), shoot dry weight (SDW) yield, and nutritional status of soybean. The five Zn rates 0, 3, 6, 9, and 12 kg ha^?1 were used in two soybean varieties [BRS 133 (conventional—NGM) and its essentially derived transgenic line BRS 245RR (GM), which was divided into: with (+Gly) and without (–Gly) glyphosate application. Only the P (phosphorus) and Zn available concentrations in the soil were impacted by Zn rates. However, the available P concentration only decreased in the soil planted with GM soybean. Mehlich 1 and diethylenetriaminepenta acetic acid–triethanolamine (DTPA–TEA), 7.3 extractants were effective to determine the available Zn. In the two crop sites, the number of pods per plant (NPP) and the SDW yield were affected by the interaction varieties × Zn. SY was influenced by the application of the herbicide, reducing a potential phytotoxic effect with the use of high rates. Regarding the nutrients, only the foliar calcium (Ca), boron (B), iron (Fe), and manganese (Mn) concentrations were negatively affected by glyphosate, and in the case of Zn, the difference occurred only between the varieties BRS 133 and BRS 245RR.     

Yield and Heavy Metal Content of Wastewater-Irrigated Cauliflower and Soil Chemical Properties

A two-year field study was conducted to determine the effects on the growth, yield, heavy metal content, and water use of cauliflowers and on the soil chemical properties of irrigation with reclaimed urban wastewaters (filtered, aerated, diluted) by comparing with fresh water under semi-arid climate conditions. Cauliflower curd yield, water use efficiency, and heavy metal contents were found to be the highest in the filtered wastewater application. Cadmium (Cd) content was just over the critical level for human health. Filtered and aerated wastewater applications created higher soil salinity, organic matter, and total nitrogen (N), dipotassium oxide (K₂O), and phosphorus pentoxide (P₂O₅) contents. Copper (Cu), iron (Fe), and manganese (Mn) contents in the surface soil were also found to be significantly higher. Treated-wastewater irrigation could increase cauliflower yield and water productivity. However, higher heavy metal contaminations under these conditions may increase health risks. Therefore, the diluted wastewater application may be preferred, but it must be utilized while taking human health into account.     

Response of Soybean to Phosphorus Fertilization in Brazilian Oxisol

Soybean is an important grain crop for Brazil, and phosphorus (P) plays an important role in improving yield of this crop in Brazilian Oxisols. Data are limited on influence of P sources and rate on soybean yield, yield components, and P-use efficiency. A field experiment was conducted for 3 consecutive years to determine response of soybean to three fertilizers (single superphosphate, Yoorin, and Arad) with 0, 17.5, 35, and 52.5 kg P ha^?1 (0, 40, 80 and 120 kg P₂O₅ ha^?1). Grain yield was significantly influenced by phosphorus fertilization. Overall, maximum grain yield was produced by application of single superphosphate, followed by Yoorin and Arad. Number of grains per pod and 100-grain weights were also influenced significantly by P fertilization. Shoot dry weight, number of pods per plant, and grain harvest index had a significant positive association with grain yield. Phosphorus uptake in grain was about six times more than uptake in shoots, and P uptake in grain had a significant positive association with grain yield. Phosphorus-use efficiency (kg grain/kg P applied or uptake) decreased with increasing P rate, and it was greater for single superphosphate than for Yoorin and Arad sources of P fertilization. However, P-utilization efficiency (kg grain plus straw yield / P uptake in grain plus straw) was greater under Yoorin treatment compared to the two other sources of P.     

Grain Yield,Yield Components,Soil Fertility,and Biological Activity under Organic and Conventional Rice Production Systems

A field experiment was conducted for 2 years on a clayey Vertisol to compare the organic and conventional methods of rice farming. Two main plot treatments were with and without plant protection and four subplot treatments were (1) control (CON); (2) inorganic fertilizers (CF); (3) organics (OF), and (4) inorganics + organics (integrated nutrient management, INM). The organics were green manure, paddy straw, and poultry manure. After 2 years, the main plot effects were not significant in terms of crop productivity though there was a reduction in soil biological parameters. Increase in grain yield was larger with inorganics and INM as compared to the organics because of the higher panicle number. However, organics increased the microbial populations, biomass carbon, nitrogen, enzyme activities, and soil fertility as compared to inorganics. Thus, organics improved the nutrient availability by influencing the soil biological activity although it did not reflect in greater yields.     

Influence of Lime and Gypsum on Growth and Yield of Upland Rice and Changes in Soil Chemical Properties

Upland rice is an important crop in the cropping systems of South America, including Brazil. Two greenhouse experiments were conducted to determine influence of lime and gypsum on yield and yield components of upland rice and changes in the chemical properties of an Oxisol. The lime rates used were 0, 0.71, 1.42, 2.14, 2.85, and 4.28 g kg^?1 soil. The gypsum rates were 0, 0.28, 0.57, 1.14, 1.71, and 2.28 g kg^?1. Lime as well as gypsum significantly increased plant height, straw and grain yield, and panicle density in a quadratic fashion. Adequate lime and gypsum rates for maximum grain yield were 1.11 g kg^?1 and 1.13 g kg^?1, respectively. Plant height, straw yield, and panicle density were positively related to grain yield. Lime as well as gypsum application significantly changed extractable calcium (Ca), magnesium (Mg), hydrogen (H)+aluminum (Al), base saturation, and effective cation exchange capacity. In addition, liming also significantly increased pH, extractable phosphorus (P) and potassium (K), calcium saturation, magnesium saturation, and potassium saturation. Optimum acidity indices for the grain yield of upland rice were pH 6.0, Ca 1.7 cmol_c kg^?1, base saturation 60%, and calcium saturation 47%. In addition, upland rice can tolerate 42% of acidity saturation.     

Zinc and amino acids on wheat-soybean intercropping under no-till management

Abstract

Foliar fertilization with micronutrients and amino acids (AAs) has been used to increase the grain yield and quality of different crops. The aim of the present study was to evaluate the effects of Zn and AAs foliar application on physiological parameters, nutritional status, yield components and grain yield of wheat-soybean intercropping under a no-till management. We used a randomized block experimental design consisting of eight treatments and four replicates. The treatments were five Zn rates (0, 1, 2, 4 and 8?kg ha^?1) and 2?L ha^?1 of AAs and three additional treatments: a control (without the Zn or AA application), 2?kg ha^?1 Zn and 2?kg ha^?1 Zn + 1?L AA. The treatments were applied by spraying during the final elongation stage and at the beginning of pre-earing for the wheat and in growth stage V6 for the soybean for two crop years in a Typic Oxisol (860?g kg^?1 clay). Zinc foliar fertilization increased the wheat grain Zn concentrations. The Zn rates and AA foliar fertilization in soil with did not affect the physiological parameters, nutrient status or yield components. The AA application at the different concentrations tested changed the soybean grain yield and the leaf N concentration. The results suggest that Zn and amino acids application increases the grains Zn concentration in the wheat, being an important strategy to agronomic biofortification.     

Variation in Yield,Phosphorus Uptake,and Physiological Efficiency of Wheat Genotypes at Adequate and Stress Phosphorus Levels in Soil

Genetic differences among crop genotypes can be exploited for identification of genotypes more suited to a low‐input agricultural system. Twenty wheat (Triticum aestivum L.) genotypes were evaluated for their differential yield response, phosphorus (P) uptake in grain and straw, and P‐use efficiency at the zero‐P control and 52 kg P ha^?1 rates. Substantial and significant differences were obvious among genotypes for both grain and straw yields at stress (8 mg P kg^?1 soil, native soil P, no P addition) and adequate (52 kg P ha^?1) P levels. Genotype 5039 produced maximum grain yield at both P levels. Relative reduction in grain yield due to P‐deficiency stress [i.e., P stress factor (PSF)] ranged between none and 32.4%, indicating differential P requirement of these genotypes. Pasban 90, Pitic 62, Rohtas 90, Punjab 85, and line 4943 did not respond to P application and exhibited high relative yield compared to those at adequate P level. FSD 83 exhibited the best response to P with maximum value for PSF (32.4%). Genotypes were distributed into nine groups on the basis of relationship between grain yield and total P uptake. Rohtas 90 and lines 4072 and 5039 exhibited high grain yield and medium P uptake (HGY‐MP). However, line 5039 with high total index score utilized less P (12.2 kg P ha^?1) than line 4072 and Rohtas 90 (13.5 and 13.6 kg P ha^?1, respectively). Moreover, this genotype also had greater P harvest index (PHI, %) and P physiological efficiency index (PPEI) at stress P level. Pasban 90, Pitic 62, and Pak 81 had the greatest total index score (21), mainly due to high total P uptake, but yielded less grain than lines 5039 and 4072 under low available P conditions. Line 6142 had minimum total index score (15) and also produced minimum grain yield. A wide range of significant differences in PPEI (211 to 365 kg grain kg^?1 P absorbed at stress and 206 to 325 kg grain kg^?1 P absorbed by aboveground plant material at adequate P) indicated differential utilization of absorbed P by these genotypes for grain production at both P levels. It is concluded from the results that wheat genotypes differed considerably in terms of their P requirements for growth and response to P application. The findings suggest that PSF, PHI, and PPEI parameters could be useful to determine P‐deficiency stress tolerance in wheat.     

Salinity Effects on Yield and Yield Components of Contrasting Naked Oat Genotypes

ABSTRACT

Global crop production systems are challenged by the increasing areas of saline soil in arid and semi-arid regions. Two naked oat (Avena sativa L.) lines (‘VAO-7’ and ‘VAO-24’) with distinct seedling tolerance to salinity were subjected to six levels of salt concentrations in a controlled greenhouse, and the response of yield and yield components to salinity stress was determined. The salt treatments 50, 100, 150, 200, and 250 mM sodium chloride (NaCl) (corresponding to EC: 3.42, 6.74, 9.66, 12.40, 15.04 dS m^?1) imposed through modified Hoagland solution. Plain Hoagland was used as control. Complete nutrient elements were provided during the entire growth period. At maturity, the number of tillers with emerged heads was counted; the plant was then harvested and separated into shoots, seeds, and roots. Both plant height and days to maturity were shortened with increasing salt stress. Among the yield components, spikelet, tiller number, and grain dry weight per plant were significantly reduced by increasing salt concentration. Number of spikelets and grain weight per plant were the most salt-sensitive yield components. Thousand grain weight also varied as salinity stress increased. Harvest index remained relatively unchanged until the salinity reached 150 mM and higher. Our data indicate that grain yield reduction in oat due to salinity stress is associated with reduced number of grains per plant and mean grain weight.     

Influence of Nitrogen on Growth,Yield, and Yield Components and Nitrogen Uptake and Use Efficiency in Dry Bean Genotypes

Dry bean is an important legume and nitrogen (N) deficiency is one of the most yield-limiting factors in most of the bean-growing regions. A greenhouse experiment was conducted with the objective to determine influence of N on growth, yield, and yield components and N uptake and use efficiency of 23 dry bean genotypes. Straw yield, grain yield, yield components, maximum root length, and root dry weight were significantly increased with the addition of N but varied with genotypes. The N × genotype interactions were also significant for most of these traits, indicating variation in responses of genotypes with the variation in N levels. There was significant difference in N uptake and use efficiency among genotypes. Most of growth and yield components were significantly and positively associated with grain yield. Based on grain yield efficiency index (GYEI), genotypes were classified into efficient, moderately efficient, or inefficient group in N-use efficiency. Nitrogen concentration was greater in grain compared to straw, indicating greater N requirement of dry bean genotypes.     

Yield,yield components,soil fertility,and nutritional status of soybean as influenced by limestone and copper interactions

Abstract

Continuous limestone application can inhibit the copper (Cu) uptake by plants. This experiment was carried out in greenhouse conditions using two soils (Typic Oxisol and Typic Entisol) with different clay and soil organic matter (SOM) levels to evaluate the effects of liming on Cu fertilization. The treatments consisted of two dolomitic limestone rates (0 and 7.5?g per pot, equivalent to 0 and 5.0?Mg ha^?1) and five Cu rates (0, 2, 4, 8, and 16?mg kg^?1). Regardless of the soil type, the limestone and Cu rate interaction did not affect the grain yield (GY), however, they did increase the productivity, shoot dry weight yield (SDWY), number of grains per pod, number of pods per pot, pod weight per pot, weight of 100 seeds, root volume, photosynthetic rate, and chlorophyll, and Ca, Mg, and Cu contents in the soil and leaves. It was concluded that for soybeans cultivated in Typic Entisol and Typic Oxisol, there was no association between 5.0?Mg ha^?1 of limestone and the Cu rates. However, in isolation, limestone and Cu rate caused a significant increase in the soybean productivity, physiological components, and yield characteristics.