Grain Yield Of Maize Research Articles

Nitrous oxide emissions and maize yield as influenced by nitrogen fertilization and tillage operations in upland soil

Previous studies simply focused on determining nitrous oxide (N2O) emissions from the soil under different tillage operations and nitrogen (N) fertilizations without considering crop yield. Therefore, the objective of this study was to determine the effects of different tillage operations and N fertilizations on N2O emissions and crop yield from upland soil. Two different tillage operations [conventional tillage (CT) and no-tillage (NT)] and N fertilizations [without urea (WOU) and with 186 kg N ha−1 of urea (WU)] were established in a randomized block design with three replications on upland soil. Maize (Zea mays) was cultivated from 6th July to 4th October, 2018 (year 1), and from 15th April to 26th July, 2019 (year 2). The daily N2O flux did not peak soon after tillage operation and N fertilization, but it was more related to the change in water-filled pore space (WFPS). The mean value of WFPS across N fertilizations and seasons (years) was higher in CT than in NT. The changes of nitrification and denitrification rates could be attributed to the differences in WFPS between CT and NT. Nitrification was the predominant process producing N2O with CT, but denitrification was with NT. The application of urea increased cumulative N2O emissions, while CT also increased it compared with NT. The order of the mean values of cumulative N2O emissions across seasons from the highest to the lowest was as follows: CT + WU (7.12 kg N2O ha−1 year−1) > NT + WU (5.69 kg N2O ha−1 year−1) ≥ CT + WOU (5.02 kg N2O ha−1 year−1) > NT + WOU (4.24 kg N2O ha−1 year−1). Tillage operation did not affect the grain yield of maize or yield-scaled N2O emissions (YSNE). However, the application of urea increased the grain yield of maize and decreased YSNE, implying it could reduce N2O emission per unit of maize grain production. No-tillage management did not decrease YSNE value compared to CT operation, but N fertilization significantly decreased YSNE in the current study.

Copper Nanoparticle Application Enhances Plant Growth and Grain Yield in Maize Under Drought Stress Conditions

Abiotic stresses, including drought, detrimentally affect the growth and productivity of many economically important crop plants, leading to significant yield losses, which can result in food shortages and threaten the sustainability of agriculture. Balancing plant growth and stress responses is one of the most important functions of agricultural application to optimize plant production. In this study, we initially report that copper nanoparticle priming positively regulates drought stress responses in maize. The copper nanoparticle priming plants displayed enhanced drought tolerance indicated by their higher leaf water content and plant biomass under drought as compared with water-treated plants. Moreover, our data showed that the treatment of copper nanoparticle on plants increased anthocyanin, chlorophyll and carotenoid contents compared to water-treated plants under drought stress conditions. Additionally, histochemical analyses with nitro blue tetrazolium and 3,3′-diaminobenzidine revealed that reactive oxygen species accumulation of priming plants was decreased as a result of enhancement of reactive oxygen species scavenging enzyme activities under drought. Furthermore, our comparative yield analysis data indicated applying copper nanoparticles to the plant increased total seed number and grain yield under drought stress conditions. Our data suggest that copper nanoparticle regulates plant protective mechanisms associated with drought tolerance, which is a promising approach for the production of drought-tolerant crop plants.

Effects of Lime and Compost on Acidic Soil Amelioration and Grain Yield of Maize at Jimma, Southwestern Ethiopia

Maize is the third important cereal crop globally after wheat and rice. Though it is consumed in all regions of Ethiopia, the crop is used as stable food in western and south western part of the country. However, Soil acidity and nutrients depletion are serious limitations in maize productivity improvement. Now a day, increasing maize production through expansion of cultivable land is no more possible. Productivity of the crop on less fertile acidic soils can be improved by integrated use of soil amendments like lime, compost as well as farm yard manure and proper fertilizer management. In Ethiopia, integrated approach of soil fertility management is attractive prime importance these days. The objective of this study is to evaluate effects of manure (FYM),compost, and their interactions with lime and inorganic fertilizers on soil properties and maize productivity . The experiment was conducted for consecutive cropping seasons 2010-2013 at Melko Jima Agricultural Research Center,. The Center is found in South Western Ethiopia; in Oromiya National Regional State and located at 7°40'47"N latitude and 36°49'47"E longitude. The mean maximum and minimum temperature of the Center are 26.2 and 11.3°C respectively. The elevation of the Center is 1,753m above sea level and it receives 1,529.5mm average annual Rainfall. The design was RCB design with three replications. Combinations of organic, inorganic fertilizers and lime significantly (P < 0.05) influenced maize grain yield in all cropping seasons. The result also revealed that in the first cropping season, recommended NP gave significantly higher yield than other combinations. On the other hand, recommended NP + recommended lime resulted in significantly higher grain yield than other combinations in 2011 and 2012 cropping seasons. It is shown that application of organic, inorganic fertilizers and lime significantly affected soil properties such as pH, exchangeable acidity, available phosphorus organic carbon content and cation exchange capacity. Accordingly, the use of compost alone, compost and lime significantly improved soil reaction in relation to other combinations. However the use of N and P and its combinations with organic fertilizer and lime did not improve soil pH. This indicates the soil acidity aggravate effect of ammoniac fertilizes. Compost, together N and P, compost with lime as well as half of compost, lime and recommended N and P significantly lowered exchangeable acidity of the soil. The use of compost alone and as well as compost and lime simultaneously significantly increased available P in soil solution relative to other combinations. It was also observed that application of compost alone and simultaneously with lime improved CEC and organic carbon stack of the soil. Generally, the use of integrated compost, manure , lime and in directly and indirect improving soil chemical and physical properties. provide significant quantities of available nitrogen, P, Mo and B, and more favorable conditions for microbial mediated reactions. Integrate use of lime, organic nutrient sources and inorganic fertilizers are beneficial in improving maize productivity and ameliorating properties of acid soil. Keywords: C ompost, Exchangeable acidity, FYM, Lime, P fertilizer, Soil pH DOI: 10.7176/JNSR/12-3-03 Publication date: February 28 th 2021

A novel strategy for microbial conversion of dairy wastewater into biofertilizer

Dairy industry generates copious amount of wastewater from its milk processing unit (1–10 m3 of wastewater per m3 of processed milk) which needs to be treated before getting discharged. The conventional treatment processes are tedious, energy intensive, and an additional burden for the dairy industry. This study attempts to develop an alternative strategy to convert the dairy wastewater into liquid biofertilizer. A tailor-made microbial consortium-based biofilm reactor with 8.64 m3 d−1 processing capacity, within 16 h of hydraulic retention time (HRT) at ambient temperature produced biofertilizer containing 96.01 mg L−1 ammonia from dairy wastewater at a flow rate of 360 L h−1 with associated 73.72% nitrate, 72.46% phosphate, 61.30% Biological Oxygen Demand (BOD) and 57.23% Chemical Oxygen Demand (COD) reduction. A similar system of 10.94 m3 d−1 processing capacity at 456 L h−1 flow rate produced 298.79 mg L−1 ammonia with nitrate, phosphate, BOD and COD reduction of 42.71%, 84.80%, 89.55% and 76.68% respectively. This liquid biofertilizer could enhance grain yield in maize (Zea mays var. Vijay) by 1.19-fold. It increased biomass yield in Sorghum Sudan grass (Sorghum sudanense) by 3.5-folds and Lemongrass (Cymbopogon citratus var. Dhanitri and var. Krishna) by 2.1 and 2.64 folds respectively. It enhanced gel content in Aloe vera (Aloe elongata var. Ghikuari) by 1.63-folds when compared to chemical fertilizer treatment. This single-step dairy wastewater treatment system requires ten times less energy with the development of a value-added product (biofertilizer). It could make the dairy wastewater management a revenue earning (USD 10.28 d−1 for 600 m3 d−1 processing capacity reactor), eco-friendly, zero discharge process preventing the use of freshwater and chemical fertilizer in agriculture, and saving 89.99% carbon dioxide equivalent (CO2 eq.) gas emission leading to environmental protection.

Effects of Sewage Sludge Stabilization Processes on Soil Fertility, Mineral Composition, and Grain Yield of Maize in Successive Cropping

The final disposal of sewage sludge (SS) in agricultural areas is considered economically and environmentally viable, but few studies on the effects of sludge stabilization processes on SS fertilizing potential are available. The present study evaluated two forms of SS stabilization on the shoot biomass, yield, and concentration of nutrients in the soil and plants in three successive maize croppings. The raw sludge was chemically stabilized (CSS) and composted (TSS) through the addition of calcium oxide and co-composting with plant residues, respectively. Five rates of each type of SS (0, 10, 20, 30, and 40 t ha−1 dry weight) were applied to the soil in a family farm of NE Brazil. A mineral fertilization treatment was used to assess the SS fertilizer potential. Changes in soil chemical characteristics (pH, organic matter, and nutrient available contents), plant mineral composition, and maize biomass and yield were assessed at each crop cultivation. Applying sewage sludge to the soil elevated the soil organic matter and the availability of N, P, Fe, Mn, Zn, and Cu, reflecting in higher accumulation of these nutrients by plants. The CSS was more efficient in increasing soil pH than SS composting. In the first harvest, maize yield in CSS was 34% higher than that obtained with mineral fertilization. The two types of sludges had different effects on soil characteristics, plant mineral composition, and maize yield. The CSS residual effect on soil pH can dismiss soil liming. Composted sludge maintained higher soil organic matter levels in the soil with the successive croppings and promoted higher soil N concentrations in the first two croppings. Both sludges increased and maintained adequate available P concentrations in the soil throughout the successive crops. The results support SS’s efficiency in providing nutrients to plants, improving soil properties, and boosting crop productivity in low-input agriculture systems.

Integrated Use of Organic And Inorganic Fertilizers on Maize (Zea Mays L.) Yield and Soil Fertility in Andisols Soil of Sidama, Ethiopia

The study was carried out to determine the influence of organic and inorganic fertilizers on maize yield and soil fertility; to determine economically optimum organic and inorganic fertilizer combinations for maize production. The study was performed in a randomized complete block design consisting of 10 treatments and 3 replications. The treatments were: Control, 100% of R-NP (138 N and 92 P), 100% of vermicompost,100% of conventional compost, 25% R-NP+75% of vermicompost, 50% of R-NP+50% of vermicompost, 75% of R-NP+25% of from vermicompost, 25% of R-NP+75% of conventional compost, 50% of R-NP+50% of conventional-compost, 75% of R-NP+25% of conventional-compost. All rates of vermicompost and conventional compost were applied based on N equivalence. Results indicate that applications of inorganic fertilizers with a combination of organic source fertilizers were increases maize yield and yield components and improve the nutrient status of the soil. The highest maize grain yield (7494.3 kg ha-1) and above-ground biomass yield (18718.0 kg ha-1) were obtained from the applications of 50% recommended NP fertilizer plus 50% vermicompost which is based on the recommended N equivalent respectively. Similarly, we found that a combination of both inorganic and organic fertilizers application also is the best strategy to improve major soil nutrients, maintain soil fertility. The economic analysis revealed that the highest net benefit of (108,872.00 ETB ha-1) was obtained from the application of 50% recommended NP fertilizer plus 50% vermicompost based on the recommended N equivalence. Yet, the lowest yield and net benefit value were attained from the control or unfertilized plot. Therefore, this study suggests that an appropriate proportion of organic fertilizer with inorganic fertilizer not only for higher yield maize production with an assurance of potential economic returns to the small hold farmers but also improve and maintain the soil fertility and should be adopted with similar soil type and agro-ecologies.

Biomass yield, chemical composition and in vitro digestibility of maize leaves defoliated at different times

This experiment was conducted to determine the effect of defoliation time on the productivity of maize, forage and in vitro digestibility of maize leaves (ML). The response of grain yield, plant height, days to 50% silking, ear height and leaf yield as well as the chemical composition of ML variety "Obasuper" to defoliation time were evaluated in a randomized complete block design with four defoliation treatments 3, 6, 9 weeks after planting (WAP) and undefoliated treatment replicated four times. Results showed that defoliating maize at 9 WAP and beyond did not have any significant (P>0.05) effect on the grain and leaf yield as well as other yield components of maize. Grain and leaf yield at 9 WAP averaged 2778.35 and 975.74 DM kg/ha respectively. The DM, crude protein (CP) and fibre fractions contents of ML varied significantly (P<0.05) among the defoliation treatments with maize defoliated at 9 WAP having a CP content of 12.6%. Ether extract and ash contents were not affected (P>0.05) by defoliation time. The in vitro digestibility of ML decreased significantly (P<0.05) with increase in the time of defoliation ranging from 59.2 and 66.4%. IT was concluded that maize variety "Obasuper" can produce forage of high quality and quantity when defoliated 9 weeks after planting wihout any anyadverse effect on the grain yield of maize.

Improving productivity of maize-lentil rotation in alkaline Fluvisol following soil test crop response (STCR) - targeted yield approach of nutrient management

ABSTRACT Soil-test crop response (STCR) approach is aiming to precise adjustment of fertilizers under varying soil-test values for targeted-yield, presently gaining recognitions for sustainable nutrient management. The study aimed to envisage the precision scale of STCR targeted-yield models in maize-lentil rotation in alkaline Fluvisol under sole-fertilizer and integrated nutrient management (with farmyard manure). Fertility-gradient, test-crop diagnostic, and validation trials were conducted following STCR technical program. Soil fertility gradient and variable fertilizer doses had caused a large variation in grain yield of maize (0.99–4.94 t ha−1, CV = 30%) and lentil (1.11–2.02 t ha−1, CV = 13%). Lentil had increased potential to utilize soil nutrient pools; in contrast, maize was highly responsive to fertlizer nutrients. Multivariate-regression analysis revealed that fertilizers N, P, and S had a strong and direct influence on maize yield; where fertilizer-P was the primary yield-determining variable for lentil. Both sole-fertilizer and integrated STCR-based treatments attained the targeted-yields in maize. However, STCR treatments could not attain the targeted-yields in lentil (17–29% deviation), but had yield advantage over the blanket recommended fertilizer dose. Hence, in tropical-alkaline soils, integrated STCR targeted-yield approach could be the sustainable nutrient management option(s) for improving the productivity of the maize-lentil system.

Effects of Integrated Use of Lime and Nitrogen Fertilizer Rate on Maize (<i>Zea mays</i> l.) Crop and Its Profitability on Nitisols, Ethiopia

In the highlands of Ethiopia soil acidity is the limiting factor for crop production due to leaching effects of basic cations, nutrient loss by erosion, crop residue removal from farmland and other human induced factors. This study was carried out at Burie <i>district </i>to determine the effect of integrated use of lime and nitrogen fertilizer rate on yield and yield components of Maize in acidic nitisols. The treatments include lime (0 and 0.5 t ha^-1) and nitrogen fertilizer (0, 100, 200, 300, and 400 kg ha^-1). To fulfill the law of minimum, 200 kg ha^-1 die ammonium phosphate (DAP) which is recommended rate of NPS (19% N, 38% P₂O₅ and 7% S) fertilizer was used uniformly to all plots at the time of planting. The maize variety BH-661 was used as a test crop. The experiment was laid out in a randomized complete block design (RCBD) with ten treatments replicated three times. Yield and yield components of maize were collected and analyzed. The analysis of variance result revealed that, interaction effect of lime and N fertilizer reduced the tasseling period (88 days in the application of 0.5 t ha^-1 lime with 100 kg ha^-1 N to 85 days in combined use of 0.5 t ha^-1 lime with 400 kg ha^-1 N) and silking period from 91 days to 88 days. Grain yield was highly and positively correlated with AGDB (r=0.996) and HI (r=0.987). Grain yield of maize in the study area was increased from 5,550 kg ha^-1 to 6,410.20 kg ha ^-1 (adjusted yield). Yield increment was 13.42%. The average maize yield in the region was 3,780 kg ha^-1 but in the study area the adjusted yield was 6,410.20 kg ha^-1. As compared with regional maize yield it was increased by 40.3%. However, yield was highly and negatively correlated with DT (r=-0.957) and DS (r=-0.925). The maximum agronomic use efficiency of (3.76%) was from Treatment 10 (0.5 t ha^-1 lime with 400 kg ha^-1 N) than Treatment 7 (0.5 t ha^-1 lime with 100 kg ha^-1 N) of (3.16%). Based on the economic analysis, the net benefit value 47,701.04 Ethiopian Birr. Therefore, integrated application of 0.5 t ha^-1 lime and 300 kg ha^-1 Nitrogen fertilizer is economically reasonable and recommended to the farmers.

Increasing maize productivity by presowing usage of biologies Mycofriend, Mikovital and Florobacillin

The aim is to study how presowing usage of biologies Mycofriend, Mikovital and Florobacillin influences on biometric indicators of maize, its productivity and soil moisture holding capacity. Using mycorrhizal fungi and nitrogen-fixing bacteria, we have received positive results about their influence on plant growth and development and maize yield forming. Leaf surface area in variants with fungiTrichoderma harzianumRifai(Mycofriend bio-based product), andTuber melanosporumVittad(Mikovital bio-based product) and bacteriaBacillus subtilisCohn. (Florobacillin bio-based product) was counted on 30th, 60th, 90th and 120th days of vegetation and was estimated by 11.2–90.0% higher compared to the control. Leaf mass and root system mass exceeded control indicators by 24.0–48.9%, respectively. Plants height in these accounted periods was higher by 4.0–31.5% compared to the control. In addition, in these variants, soil moisture holding capacity increased by 7.3–38.1%, share of soil lumps smaller than 0.25 mm decreased by 2.8–7.2%. Grain yield of Maize in variants with mycorrhizal fungi and nitrogen-fixing bacteria was 1.64–2.68 t/ha higher than in the control. It should be noted that presowing usage of fungusTrichoderma harzianumRifaion plants seeds, provides better efficiency on plants’ growth and development and their productivity.

ВПЛИВ УДОБРЕННЯ ТА ВАПНУВАННЯ НА ПРОДУКТИВНІСТЬ КУКУРУДЗИ НА ЗЕРНО В КОРОТКОРОТАЦІЙНІЙ СІВОЗМІНІ НА ДЕРНОВО-ПІДЗОЛИСТОМУ ГРУНТІ

The results of the influence of doses and forms of limestone ameliorants and fertilization on the maize productivity in the Western Polissia were shown. The ameliorants application on the background of mineral fertilizers increased the indicators of the yield structure and plant survival. The highest results were obtained with the use of 1.5 dose dolomite meal by the hydrolytic acidity of: plants density before harvesting 62.4 ths. pcs/ha, plants height of 229 cm, the weight of an ear was 223 g, the grain yield from an ear was 79.7 %. The limestone ameliorants and fertilizers application also had a positive effect on the yield and pro-tein content in maize grain. According to the obtained data, it was found that the protein content in the grain increased by 1.82–2.89 % in variants with melioration on the background of N120P90K120 compared to the control, and amounted to 9.4–10.5 %. The maximum 10.5 % of the protein content was obtained by the using a 1,0 dose of dolomite meal on the background of mineral fertilization with the addition of sulfur S40 and foliar dressing of the Nutrivant Plus Cereals micronutrient fertilizer (2 kg/ha). The highest yield of 9.04 t/ha was formed by the combined use of 1.5 dose of dolomite meal by the hydrolytic acidity and the recommended rate of mineral fertilizers (N120P90K120). The increase of maize yield compared to control (without fertilizers) was 4.99 t/ha, compared to the background (N120P90K120) – 3.98 t/ha. The grain yield of maize increased by 10.3 % due to the application of sulfur fertilizer (S40) and two-time foliar fertilization with Nutrivant Plus Cereals micronutrient fertilizer (2 kg/ha). The analysis of economic efficiency showed that the cultivation of grain maize was unprofitable at the N120P90K120 application without soil liming; while when using chemical ameliorants, in particular different doses of dolomite meal, on a similar background fertilizer the maize cultivation was profitable (in the range of 6174–16024 UAH/ha) Keywords: chemical ameliorants, doses, fertilizers, yield, maize.

УРОЖАЙНІСТЬ ТА ЕКОНОМІЧНА ОЦІНКА ВИРОЩУВАННЯ КУКУРУДЗИ НА ЗЕРНО ЗА РІЗНОГО РІВНЯ ЗАБРУДНЕННЯ АГРОЕКОТОПІВ ПОЛЮТАНТАМИ

In Ukraine, as in the rest of the world, the part of lands contaminated with pollutants, in particular, heavy metals, is growing. However, on these lands it is possible to grow crops that provide safe, economically viable products. The study of the maize agrocenosis state in the conditions of soil contamination with lead, cadmium, zinc testified that the crops have the high resistance to the increase of metal content in the soil environment. Maize as a grain crop has a high viability and buffer barrier to pollutants. It is able to partially accumulate and fix the metals by the root system, bringing to the commodity part of the crop only a small proportion of them, not exceeding the maximum allowable concentration, and reduce the risk of further expansion of areas contaminated with these ecotoxicants. The variants are provided by the experiment allowed to obtain a grain yield of 7.36–9.32 t/ha (average level of variation 10.24 %). In plots with 5–100-fold excess of the background of heavy metals, the grain yield tended to a reducing by1.16–1.96 t/ha (LSD05 = 1.88) compared to the control, i.e. the loss of maize yield was 12–21 %. It was found that soil contamination with pollutants led to a decrease in yield and profit compared to the natural background (control). The maximum income (14 575 UAH/ha) was obtained in the variant with a natural background, which is associated with a high yield of maize grain. The analysis of research results showed that the profitability of maize grain production at the yield of 7.36–9.32 t/ha varied according to the level of ecotope contamination with pollutants and amounted to 31–63 %. The profitability is indicator that makes it possible to comprehensively assess all factors. The cultivation of maize in areas with soil contamination with heavy metals exceeding by 5 and 10 times the natural background provided a level of profitability of 39 and 44 %, respectively, and was economically feasible. This allowed to effectively use the agriculture lands with constantly renewed soil contamination for profit from the cultivation of agricultural products while preventing the expansion of the contamination area. Key words: corn, heavy metals, yield, profit, economic efficiency, profitability.

Non-herbicidal Weed and Organic Nutrient Management in Maize under Rainfed Maize-Sesamum Cropping Sequence

During 2013 and 2014, a field experiment was performed in the Instructional-Cum-Research Farm, Assam Agricultural University, Jorhat to study the effect of weed and nutrient management in maize on weeds and maize, sesamum yield. The field experiment was conducted in split plot design (SPD) and the treatments comprised of fertility management (F0 - control, F1 - 2.5 t/ha enriched compost and F2 - 5.0 t/ha enriched compost) as the main factor and weed management (W0-no weeding, W1- hand hoeing and earthing up 20 and 50 days after sowing,W2-in situ cowpea mulching upto 50 days after sowing and W3- in situ blackgram mulching upto 50 days after sowing) as the sub factor in maize and its residual effects tested in subsequent sesamum crop. It was found that W1 resulted in the least weed NPK content (%) at 60 days after sowing (DAS). In case of NPK uptake (kg/ha), W1 resulted in the least at 60 DAS and harvest. It was also noticed that W2 caused the least weed NPK content (%) at harvest during both the years. Organic nutrition had no effect on the above mentioned parameters. The residual effect of weed management and organic nutrition in the subsequent sesamum crop was nil in terms of weed suppression. It was found that W1, F2 and W1F2 resulted in significantly the best LAI of maize for both the years. Treatments W1 (3014.59 kg/ha and 2849.24 kg/ha in 2013 and 2014, respectively), F2 (2322.33 kg/ha and 2178.29 kg/ha during 2013 and 2014, respectively) and W1F2 (4723.81 kg/ha and 4507.24 kg/ha during 2013 and 2014, respectively) too resulted in significantly the highest grain yield of maize. No residual effect of weed management was found while organic nutrition had residual effect in sesamum crop. The best LAI in sesamum was due to fertility management, F2 during both the years while F1 and F2 both at par resulted in the least number of days needed for 50% flowering in sesamum. In sesamum, significant interaction effect was found only during 2014 for LAI, days to 50% flowering and yield. In terms of seed yield of sesamum, F2 (589.08 kg/ha) and F1 (556.28 kg/ha) being at par were better than F0 in 2013 while in 2014, F2 (402.78 kg/ha) was the best treatment. More benefit: cost ratio (2.56 and 2.16 during 2013 and 2014, respectively) of the maize-sesamum cropping sequence was due to F1W1.

Potassium fertilization for white oat and maize in integrated crop‐livestock system under no‐tillage

AbstractIntegrated crop‐livestock systems (ICLS) are diversified agroecosystems characterized by the rotation, succession or mixtures of agricultural, livestock or forestry activities, in no‐tillage systems. In ICLS with trees, the tree modifies the light and water availability, and might generate root competition for nutrients, like potassium (K). The study aims to evaluate dry matter (DM) and macronutrients accumulation in white oat, DM and grain yield of maize, and the K use efficiency (KUE) by these crops cultivated in an ICLS with eucalyptus. The experimental design was a randomized block in a split‐plot design with three replications. Plots consisted of four cultivation positions (CP) between the tree rows, where CP1 (0 to 4 m distance) refers to a position close to the trees; CP2 (4 to 8 m distance) and CP4 (12 to 16 m distance) corresponds to two intermediate positions between rows; and CP3 (8 to 12 m distance) corresponds to a central position between rows. In subplots, four potassium oxide (K2O) annual doses were assigned, with potassium chloride being applied on the surface, where each rate was half the rate applied at sowing of each crop. DM and macronutrients accumulation in white oat shoot decreased due to eucalyptus shadow (64.5% light restriction). Responses of maize DM and grain yield to K2O addition were different among CPs, possibly owing to different light patterns. No changes in the maize yield were observed with K2O application in CP1 and CP2. However, for other positions, quadratic responses in grain yield were observed. In ICLS with eucalyptus in a subtropical region of Brazil, the reduction of K fertilization led to lower yields in white oat and maize. As KUE was high in plots with low K rate, the production cost in ICLS with trees may be decreased if massive production is not required.

Case Study upon Foliar Application of Biofertilizers Affecting Microbial Biomass and Enzyme Activity in Soil and Yield Related Properties of Maize and Wheat Grains.

Simple SummaryThe study evaluated the effects of the application of microbial inoculants (N-fixing Klebsiella planticola and Enterobacter spp.), two rates of composite mineral fertilizers, and their combination on microbial biomass carbon, dehydrogenase and proteinase activity in acid Lessivated Cambisol and yield-related properties of maize and wheat grains in a two-year trial. The results indicated that mineral fertilizers are not, in general, negative for soil microbiota when used in the context of sustainable agriculture without monoculture. It was found that the combined application of microbial inoculants and lower doses of mineral nitrogen, phosphorus, and potassium (NPK) fertilizers, increased the yield of maize and wheat compared to the use of only NPK fertilizers in our case study. The highest values of the examined parameters of soil fertility were determined in the period with better precipitation distribution during the vegetation period of the studied year due to the optimal values of soil moisture and air temperature. Concluding, the authors point out the task of science to offer the producer a solution for conducting intensive agricultural production, which must be economically and ecologically safer.This study evaluated the effects of the application of microbial inoculants (N-fixing Klebsiella planticola and Enterobacter spp.), two rates of composite mineral fertilizers, and their combination on microbial biomass carbon (MBC), dehydrogenase (DHA), and proteinase activity (PTA) in Lessivated Cambisol and yield-related properties of maize and wheat grains in a two-year trial. Unfertilized soil was used as a control variant. MBC was measured using the chloroform fumigation-extraction method, DHA was determined spectrophotometrically by measuring the intensity of the formed red-colored triphenyl formazan, while PTA was determined using a titration method by measuring the degree of gelatine decomposition. In grain samples, P was determined spectrophotometrically, K—by flame emission photometry, N—on an elemental carbon/nitrogen/sulfur (CNS) analyzer, and crude proteins—by calculation of N content. Measuring both crops’ yield was carried out at the end of the vegetation. The results indicated that mineral fertilizers are not, in general, negative for soil microbiota when used in the context of sustainable agriculture without monoculture. There is a significant increase in the values of soil MBC, DHA, and PTA in the variants with combined application of bacterial inoculants and lower rates of mineral fertilizers. The highest values of these parameters were determined in the period with a better distribution of precipitation during the vegetation period of the year. The mentioned combination also resulted in a higher grain yield of maize and wheat comparing to the application of lower rates of the NPK nutrients solely. The combined application of high rates of mineral fertilizers and bacterial inoculants resulted in significantly increased N, P, K, and protein content in the grains of crops, and the same applied to yield. Concluding, studied bacterial inoculants can be used to specify the replacement of nitrogen fertilizers, stimulating the microbial biomass and enzyme activity in the soil, helping to ensure that the supply of nutrients contributing to an optimized yield of crops is maintained.

Integrated Weed and Nutrient Management Improve Yield, Nutrient Uptake and Economics of Maize in the Rice-Maize Cropping System of Eastern India

Increasing productivity of maize while decreasing production costs and maintaining soil health are emerging challenges for the rice–maize system in South Asia. A range of integrated nutrient and weed management practices were tested in winter maize for their effects on yield, profitability, and soil health. The nutrient management treatments were a partial substitution of nitrogen with bulky (Farmyard manure; vermicompost) and concentrated organic manures (Brassicaceous seed meal, BSM; neem cake), whereas weed management practices compared chemical controls only versus an integrated approach. The N supplementation through BSM diminished the weed growth by reducing weed N uptake, and enhanced the maize crop uptake of nutrients. As compared to the sole chemical approach, atrazine-applied pre-emergence followed by hoeing reduced weed density by 58 and 67% in years 1 and 2, respectively. The N supplementation through BSM resulted in the maximum yield of maize grain (6.13 and 6.50 t ha−1 in year 1 and year 2, respectively) and this treatment increased yield in year 2 compared to N application through synthetic fertilizer. Hoeing in conjugation with herbicide enhanced the maize grain yield by 9% over herbicide alone. The maximum net return and economic efficiency were achieved with the application of BSM for N supplementation, together with the integrated weed management practice.

Strip-width determines competitive strengths and grain yields of intercrop species in relay intercropping system

Maize/soybean relay intercropping system (MSR) is a popular cultivation method to obtain high yields of both crops with reduced inputs. However, in MSR, the effects of different strip widths on competitive strengths and grain yields of intercrop species are still unclear. Therefore, in a two-year field experiment, soybean was relay-intercropped with maize in three different strip-width arrangements (narrow-strips, 180 cm; medium-strips, 200 cm; and wide-strips, 220 cm), and all intercropping results were compared with sole maize (SM) and sole soybean (SS). Results showed that the optimum strip-width for obtaining high grain yields of maize and soybean was 200 cm (medium-strips), which improved the competitive-ability of soybean by maintaining the competitive-ability of maize in MSR. On average, maize and soybean produced 98% and 77% of SM and SS yield, respectively, in medium-strips. The improved grain yields of intercrop species in medium-strips increased the total grain yield of MSR by 15% and land equivalent ratio by 22%, which enhanced the net-income of medium-strips (by 99%, from 620 US $ ha−1 in wide-strips to 1233 US $ ha−1 in medium-strips). Overall, these findings imply that following the optimum strip-width in MSR, i. e., strip-width of 200 cm, grain yields, and competitive interactions of intercrop species can be improved.

QTL Analysis and Fine Mapping of a Major QTL Conferring Kernel Size in Maize (Zea mays).

Kernel size is an important agronomic trait for grain yield in maize. The purpose of this study is to map QTLs and predict candidate genes for kernel size in maize. A total of 199 F2 and its F2:3 lines from the cross between SG5/SG7 were developed. A composite interval mapping (CIM) method was used to detect QTLs in three environments of F2 and F2:3 populations. The result showed that a total of 10 QTLs for kernel size were detected, among which were five QTLs for kernel length (KL) and five QTLs for kernel width (KW). Two stable QTLs, qKW-1, and qKL-2, were mapped in all three environments. Three QTLs, qKL-1, qKW-1, and qKW-2, were overlapped with the QTLs identified from previous studies. In order to validate and fine map qKL-2, near-isogenic lines (NILs) were developed by continuous backcrossing between SG5 as the donor parent and SG7 as the recurrent parent. Marker-assisted selection was conducted from BC2F1 generation with molecular markers near qKL-2. A secondary linkage map with six markers around the qKL-2 region was developed and used for fine mapping of qKL-2. Finally, qKL-2 was confirmed in a 1.95 Mb physical interval with selected overlapping recombinant chromosomes on maize chromosome 9 by blasting with the Zea_Mays_B73 v4 genome. Transcriptome analysis showed that a total of 11 out of 40 protein-coding genes differently expressed between the two parents were detected in the identified qKL-2 interval. GRMZM2G006080 encoding a receptor-like protein kinase FERONIA, was predicted as a candidate gene to control kernel size. The work will not only help to understand the genetic mechanisms of kernel size of maize but also lay a foundation for further fine mapping and even cloning of the promising loci.

AGRONOMIC PERFORMANCE OF MAIZE UNDER Azospirillum brasilense INOCULATION AND TOP-DRESSING NITROGEN FERTILIZATION

Maize inoculation with bacteria of the genus Azospirillum can reduce the consumption of nitrogen fertilizers to obtain maximum grain yield. In this context, the aim was to evaluate the effect of inoculation with Azospirillum brasilense associated with nitrogen fertilization on the maize agronomic performance. A randomized block design was used in a split-plot scheme with four replicates. Four inoculation managements with Azospirillum brasilense (T0 - control without inoculation; TC2 - seed box inoculation, 200x108 viable cells ha-1; TC3 - seed box inoculation, 400x108 viable cells ha-1; TS1 - previous inoculation of the seeds, 600x108 viable cells ha-1) associated with four top-dressing N doses (0, 60, 120 and 180 kg ha-1), applied at maize stage V6 by urea. Inoculation with Azospirillum brasilense associated with top-dressing nitrogen fertilization increases the number of grain rows per ear, number of grains per row, number of grains per ear and grain yield of maize, mainly due to its positive effects on plant nutrition. Managements with seed box inoculation with 400x108 viable cells per ha (TC3) and inoculation in seed pre-treatment (TS1) are the most recommended for maize.

BIOMASS YIELD FOR SILAGE AND GRAIN YIELD OF MAIZE INTERCROPPED WITH SOYBEAN

Maize is one of the main cereals produced worldwide and, in association withsoybean crop, can result in benefits to the production system. The objective of this study was to evaluate the biomass yield for silage and grain yield in maize crop, in the maizesoybean intercropping system. The study was conducted in the municipality of Dois Vizinhos - PR, Brazil, using a randomized block design, with nine treatments and four replicates. The treatments were composed of three maize hybrids grown in monoculture and in intercropping with two soybean cultivars (P1630+TMG7062, P1630+P95R51, P1630, LG6030+TMG7062, LG6030+P95R51, LG6030, P30F53+TMG7062, P30F53+P95R51 and P30F53). The data were subjected to analysis of variance and, when there was significance, Scott-Knott test was applied. Maize biomass yield for silage was approximately 4,000 kg ha-1 higher when the hybrids LG6030 and/or P30F53 were used. The cultivar TMG7062 stands out from P95R51 in terms of dry biomass yield for silage. The higher the percentage of soybean biomass added to the silage, the higher its crude protein content. However, crude protein yield per area was similar for the evaluated treatments. Some yield components (number of grains per row and thousand-grain weight) and grain yield of maize differ according to the hybrid used, but similarity is observed between intercropping and monoculture. There is evidence that the soybean cultivar TMG7062, intercropped with P1630, has the potential to reduce the grain yield of the cereal.