Maize Fertilizer Research Articles

Effect of Nitrogen Levels on Spring Maize in Relation to Mulching Materials in Central Inner Tarai of Nepal

The effect of different mulching materials and varying nitrogen fertilizer levels on growth, yield attributes, and yield of open-pollinated maize variety aiming at yield improvement was studied in inner Terai of Nepal through a field experimentation in 2019. The treatments included were the combinations of three mulching materials, (a) plastic mulch, (b) straw mulch, and (c) no mulching; and four nitrogen levels (0, 50, 100, and 150 kg ha-1) arranged in a split-plot design with four replications. Data on growth, yield attributes, and yield were taken and analyzed by using R Studio. The higher (p<0.05) heat use efficiency was recorded under plastic mulch and the higher levels of nitrogen application. The number of kernels per cob and thousand kernel weight were higher (p<0.05) in mulch treatments and higher nitrogen levels. Both the barrenness and sterility percentage were higher (p<0.05) for the 0 kg N ha-1 and reduced (p<0.05) by the nitrogen application of ≥100 kg ha-1. Increased tasseling-silking interval increased (p<0.05) the sterility and grain filling duration and increased (p<0.05) the grain yield. Due to the better yield attributes, the grain yield of mulch applied treatments and application of ≥100 kg N ha-1 were higher (p<0.05) than the no mulch and ≤50 kg N ha-1, respectively. The yield was hampered more by barrenness than by sterility. The effect of nitrogen levels on grain yield followed the quadratic relationship; 104 kg and 129-130 kg N ha-1, respectively for no mulch and mulching treatments which are estimated as economic levels of nitrogen fertilizers for open-pollinated spring maize under the central inner Terai environment.

Acidified Animal Manure Products Combined with a Nitrification Inhibitor Can Serve as a Starter Fertilizer for Maize

There is an urgent need for better management practices regarding livestock farm nutrient imbalances and for finding alternatives to the actual use of mineral fertilizers. Acidification of animal manure is a mitigation practice used to reduce ammonia emissions to the atmospheric environment during manure storage and land application. Acidification modifies manure physicochemical characteristics, among which soluble N and P significantly increase. The main objective of this study was to investigate if acidification and the addition of a nitrification inhibitor to manure and placement of the treated manure close to the seed can stimulate maize growth by enhancing nutrient availability, specially P and consequently plant P uptake, at early development stages without the use of mineral N and P as a starter fertilizer. Raw dairy slurry and solid fractions from dairy slurry and digestate from a biogas plant were acidified to pH 5.5 and applied with or without a nitrification inhibitor (DMPP, 3,4-dimethyl pyrazole phosphate) to maize in a pot experiment, where biomass productivity, nutrient uptake and soil P availability were examined. Acidification increased the water-extractable P fraction of all slurry and digestate organic residues (by 20–61% of total P) and consequently plant P uptake from solid fractions of both slurry and digestate compared to the untreated products (by 47–49%). However, higher plant biomass from acidification alone was only achieved for the slurry solid fraction, while the combination of acidification and DMPP also increased plant biomass in the digestate solids treatment (by 49%). We therefore conclude that the combination of acidification and a nitrification inhibitor can increase the starter fertilizer value of slurry and digestate products sufficiently to make them suitable as a maize starter fertilizer.

Assessing the uncertainty of maize yield without nitrogen fertilization

Abstract Maize (Zea Mays L.) yield responsiveness to nitrogen (N) fertilization depends on the yield under non-limiting N supply as well as on the inherent productivity under zero N fertilizer (Y0). Understanding the driving factors and developing predictive algorithms for Y0 will enhance the optimization of N fertilization in maize. Using a random forest algorithm, we analyzed data from 679 maize N fertilization studies (1031 Y0 observations) conducted between 1999–2019 in the United States and Canada. Predictability of Y0 was assessed while identifying determinant factors such as soil, crop management, and weather. The inclusion of weather variables as predictors improved the model efficiency (ME) from 51 up to 64 %, and reduced the root mean square error (RMSE) from 2.5 to 2.0 Mg ha−1, 34 to 27 % in relative terms (RRMSE). The most relevant predictors of Y0 were previous crop, irrigation, and soil organic matter (SOM), while the most influential weather data was linked to the radiation per unit of thermal time (Q quotient) around flowering and spring precipitations. The crop rotation effect resulted in Alfalfa (Medicago sativa L.) as the previous crop with the highest Y0 level (IQR = 11.5–15.0 Mg ha−1) as compared to annual legumes (IQR = 5.6–10.0 Mg ha−1) and other previous crops (IQR = 3.6–7.8 Mg ha−1). The Q quotient around flowering positively affected Y0, while spring precipitations and extreme temperature events during grain filling showed a negative association to Y0. Overall, these results reinforce the concept that yields are controlled not only by soil N supply but also by factors modifying plant demand and ability to capture N. Lastly, we foresee a promising future for the use of machine learning to address both prediction and interpretation of maize yield to obtain more reliable N guidelines.

Maize response to water, salinity and nitrogen levels: soil and plant ions accumulation

In the present study, some nutritional imbalances, specific ion toxicity and yield-ion concentration relationships in maize under water, nitrogen (N) and salinity stresses were assessed. Effect of different levels of irrigation water (I1=1.0ETc+0.25ETc as leaching, I2 =0.75I1 and I3 =0.5I1) as main plot, salinity of irrigation water (S1=0.6, S2= 2.0 and S3=4.0 dS m-1) as sub-plot and N fertilizer rates (N1=0, N2=150 and N3=300 kg N ha-1) as sub-sub-plot on maize (cv SC 704) were investigated in a split-split-plot design with three replications during 2009 and 2010. Results showed that salts accumulated in soil were 28.4% higher in I2 compared with other irrigation treatments. Soil nitrate concentration was statistically higher under I3 and S1 treatments (83% and 10%, respectively) compared with other irrigation and salinity levels. There was no K+ deficiency caused by salinity; however, salinity resulted in statistically lower K+/Na+ compared with no saline conditions. Plants took up 25% higher N in I2 compared with other irrigation levels. Furthermore, N uptake by plants decreased by an average of 18% under salinity condition indicating that higher N application rate above the required level under saline water application put the environment at the risk of groundwater N contamination. Results of this study confirmed the fact that Na+ accumulation in soil was more detrimental than Cl- accumulation for maize irrigated with saline water. Besides, according to threshold values for soil ions, the optimum levels of irrigation and N fertilizer for maize might be lower under saline water application. Furthermore, based on the grain yield reduction coefficient, maize required a higher level of K+ and K+/Na+ under deficit saline water irrigation for avoiding yield losses.

Investigating Organic Manure and Inorganic Fertilizer for Sustainable Maize (Zea mays) Production in Southwestern Nigeria

Aim: This research investigated the utilization of livestock manure as nutrient source in maize farming.
 Place and Duration: The field experiment was carried out at the research field of the Federal Ministry of Agriculture and Rural Development, Lagos State Field Office, Nigeria during the late planting season (July/August) of 2019.
 Methodology: An experimental field research was conducted to compare the variation in the vegetative parameters and yields of maize grown with different livestock wastes. The experiment consisted of six treatments, cattle, pig, poultry, sheep manures, NPK and control experiment set-up in a Randomized Complete Block Design with four replicates. The following data were recorded during the experiment: plant height, number of leaves, number of days to first tasselling and silking, number of cob, cob length, effective cob length, cob diameter, cob weight, ear weight, 100 grain weight, grain yield and shelling percentage. Data recorded were exposed to Analysis of Variance (ANOVA) and the means were separated with Duncan Multiple Range Test.
 Results: The plant height and number of leaves recorded at 9 Weeks After Planting were 215.53, 217.57, 219.69, 188.85, 219.19, 182.76 and 13.60, 13.40, 13.8, 12.4, 13.8, 12.2 cm for cattle, pig, poultry, sheep, NPK and control respectively while the yield were 3193.00, 3055.20, 3513.00, 2855.00, 3791.00 and 1523.80 kg/ha for cattle, pig, poultry, sheep, NPK and control respectively.
 Conclusion: Considering the yields recorded, it has shown that cattle, pig, poultry and sheep manures are suitable for sustainable maize growth and is a means of livestock waste management.

Utilization of Parkia biglobosa Leaves as Green Manure for the Fertilization of Maize (Zea mays L.) in Southern Nigeria

Aim: To investigate the use of Parkia biglobosa leaves as a source of organic nutrients for maize production.
 Place and Duration of Study: The field experiment was carried out at the research field of the Federal Ministry of Agriculture and Rural Development, Lagos State Field Office, Nigeria during the early planting season (March/April) of 2018.
 Methodology: A field research was carried out to compare the growth and yield of maize when Parkia biglobosa leaves and inorganic fertilizer were used as nutrients sources. Four factorial treatments combinations of Parkia biglobosa leaves, NPK fertilizer, combined Parkia biglobosa leaves and NPK fertilizer, and a control experiment was ordered in a Randomized Complete Block Design with four replicates. The plants height, number of leaves and surface areas were recorded at 3, 6 and 9 weeks after planting while the maize yields were considered at the end of the experiment.
 Results: The study showed that the treatment with the combination of Parkia biglobosa leaves and inorganic fertilizer produced the highest indexes of plant tallness, foliage number and surface areas. Maize yields of 2816.66, 2700, 2316.66 and 1566.66 kg/ha were recorded from treatments with Parkia biglobosa leaves and inorganic fertilizer combination, inorganic fertilizer, Parkia biglobosa leaves and the control experiment, respectively.
 Conclusion: These results reflected that the incorporated effect of Parkia biglobosa leaves and inorganic fertilizer at the rate of 50:50 gives the best maize growth and yield index.

Use of compost bedded pack barn in maize fertilization for silage

This article aims to study the effect of different time intervals for bed maturation in compost sheds for dairy cattle, such as organic manure in maize crop for silage. The experimental design was a randomized block in split-plot with five treatments, six collection times, and five replicates. The data were submitted to variance analysis and compared by Scott-Knott. Sigmoid functions of logistic growth were adjusted to the data. The treatments with addition of fresh and mature compost with nitrogen cover showed higher shoot dry matter production when compared to treatments without compost. For maize plant height, stalk diameter and number of leaves, it was observed that from 35 days after plant germination, these variables were considered superior for the treatments that received bedding. The sigmoid function was proper to represent the plant growth to the silage point. It is concluded that the use of bedding from compost sheds as an organic manure is recommended as a sustainable alternative in the reuse of waste from milk production.

In-Soil Application of NP Mineral Fertilizer as a Method of Improving Nitrogen Yielding Efficiency

This study presents the results of a four-year field experiment assessing the effectiveness of phosphorus application in maize cultivation according to the depth of two-component fertilizer (NP) placement in the soil layer, type of nitrogen fertilizer and date of application. Nitrogen utilization from mineral fertilizer was low—on average, 37.1% during the four years of research. The nitrogen metabolism index, measuring the agricultural and physiological efficiency of nitrogen use, confirmed the significant impact of NP fertilizer placement at 10 and 5 cm as optimal in maize fertilization. The use of nitrogen in maize cultivation before sowing, compared to the application of this component at the phase of 5-6 leaves BBCH 15/16 stage (stage of leaf development with five–six leaves unfolded), significantly increased the agricultural and physiological effectiveness of nitrogen applied in mineral fertilizer. Ammonium nitrate application before sowing the maize, compared to top dressing at the BBCH 15/16 stage, significantly increased nitrogen uptake and utilization from mineral fertilizer. Date of urea fertilizer application to the soil did not have a significant impact on these indicators in maize cultivation.

Integrated Nutrient Management Practices on Maize Growth Parameters, Yield Parameters and Yield of Maize

Integrated nutrient management (INM) is a management strategy that aims at maintaining or adjusting of soil fertility and plant nutrient supply to an optimum level for sustaining the desired crop productivity through all possible sources of plant nutrients in an integrated manner through a balanced use of fertilizers combined with organic sources. Growth parameters, yield components, yield of maize were highly enhanced by integrated use of chemical and organic fertilizer is crucial for assuring food security. Combined use decreases the nutrient losses by slow release and reducing the input cost of fertilizer. Different kinds of organic materials such as FYM, animal manures, green manures, crop residues, composts, and industrial wastes have been used in maize systems. The concepts and research evidences from eminent scientists proves that integrated nutrient management enhances the productivity of maize and soil fertility sustenance.

Does the higher root carbon contribution to soil under cropping cycles following grassland conversion also increase shoot biomass?

This study tested the possible root biomass improvements in crop rotations after the conversion of grasslands, and crop samples from maize, winter wheat, and winter barley were collected during 2011–2013 from a long-term experimental site in Lusignan, France (http://www.soere-acbb). Root biomass C quantification was performed using δ13C isotopic signatures to determine the presence of both C3 and C4 plants. We also calculated the recovery rate of maize root biomass C. The results showed that after crop rotations, 0–60 cm root biomass C values were 44.1, 34.2, and 18.7 g C m−2 for maize, winter wheat, and winter barley respectively. The Root biomass C of crops after conversion to grassland was approximately 2–3 times those observed after crop rotations. However, incorporating ley grassland duration into crop rotations showed limited improvements in shoot biomass C and grain yield of the crops, regardless of the decreased rate of N fertilizer for maize. Moreover, root biomass C had a significant relationship with N supply from residues (P < .05). Nevertheless, shoot biomass C of only maize showed significance in its relationships with N supply and root biomass C. In addition, in each 30 cm soil layer (0–30 cm, 30–60 cm, and 60–90 cm), the recovery rate of maize roots decreased to approximately 15% when root biomass C increased to 10 g C m−2. However, further increases in root biomass C had little impact on the recovery rate. In conclusion, compared with continuous cropland, incorporating ley grassland duration into crop rotations increases root biomass C of crops, but this change may not be a significant increase of the shoot biomass C or grain yield. This finding simply indicates the improved C input from crops and the potential to increase soil organic C, as well as providing a model for the sustainability of crop rotations.

Agronomic performance of urea in pastilled compositions applied on maize fertilization

Urea pastillation is a technology that allows the composite mixture with other elements like sulfur and zinc. This study aimed to provide recommendations of N rates, and to assess the agronomic performance of N fertilizers, including pastille urea and its composition associated with S and Zn, top-dressed on maize. Two experiments were set up in the harvests of 2014 and 2015 in an Acrisol and a Lixisol. The experimental design was the randomized blocks with three replicates in a split-plot arrangement and an additional treatment (no N). In the plot, three N applications rates were tested (75, 150 and 300 kg ha-1); while in the subplots, seven fertilizers were tested, including conventional and pastilled ones. The greater was the N rate applied, the higher were the leaf N content and grain yield of maize. The S content in the leaves increased with the increasing S doses applied with the tested fertilizers. Yields with ammonium sulfate were higher than with prilled urea, pastille urea and pastille urea with elemental S in the harvest mean on the Haplic Lixisol. The rate that corresponded to the maximum economic efficiency for UR was 128 and 119 kg N ha-1 for Haplic Acrisol and Haplic Lixisol, respectively. The recommended dose of ammonium sulfate was 119 kg ha-1, since it provided the greater incomes for both sites.

Effects of Different Rates of Poultry Manure and Split Applications of Urea Fertilizer on Soil Chemical Properties, Growth, and Yield of Maize.

During integrated nutrient management involving poultry manure (PM) and urea fertilizer (UF) for maize (Zea mays L.), it is necessary to investigate the best time to apply UF that will optimize soil chemical properties, growth, and yield of maize. Hence, studies were carried out to investigate the effect of different rates of PM and single and split applications (SA) of UF on soil chemical properties, growth, and yield of maize. The treatment involved three levels of PM (0.0, 4.0, and 8.0 t·ha−1) and four sets of periods of UF: (i) 0 kg N ha−1 (control), (ii) 120 kg N ha−1 applied at planting (AP), (iii) two SA of 120 kg N ha−1 (90 kg N ha−1 applied AP + 30 kg N ha−1 at thirty days after planting (DAP)), and (iv) three SA of 120 kg N ha−1 (60 kg N ha−1 applied AP + 30 kg N ha−1 thirty DAP + 30 kg N ha−1 at tasseling). The 12 treatments were arranged in a randomized complete block design and replicated three times. PM and UF alone and integrating UF with PM improved soil chemical properties, growth, and yield of maize compared with the control. SA of UF three times (60 + 30 + 30) had the most improved soil chemical properties, growth, and yield of maize. Results also showed that maize yielded higher under UF integrated with PM compared with their sole forms. Application of 60 + 30+30 with 8 t ha−1PM (60 + 30+30 + 8 t ha−1PM) or with 4 t ha−1PM treatments showed the highest growth and yield of maize, but due to the bulkiness, handling challenges, and cost of PM, 60 + 30+30 + 4 t ha−1PM is recommended. Therefore, for better growth and yield of maize, after the initial application of PM, UF application should be split-applied in accordance with plant growth and the pattern of uptake to avoid losses by leaching and therefore ensured that N level in the soil is high at the critical stage of N demand.

Construction of a critical nitrogen dilution curve for maize in Southwest China

There is an urgent need for suitable nitrogen nutrition models for Southwest China, which take into account nutritional differences at the cultivar level, to provide scientific guidance for cultivar-specific fertilizer applications during maize production. In this study, the nitrogen-efficient maize cultivar Zhenghong 311 and the nitrogen-inefficient maize cultivar Xianyu 508 were used in a three-year field experiment and a 2-year field pot experiment with nitrogen application rates ranging from 0 to 450 kg·hm−2 to construct a critical nitrogen dilution curve model for each maize cultivar. The usefulness of this model to diagnose nitrogen status and evaluate maize fertilization needs was subsequently analyzed. We found that the critical nitrogen concentration in maize aboveground tissues was a power function of the biomass, described by the equations Nc = 26.126 W−0.292 and Nc = 25.826 W−0.302 for ZH 311 and XY 508 cultivars, respectively. The fitting degree of these equations was significant or highly significant, demonstrating the suitability of these models to diagnose N deficiency and fertilization needs in maize plants grown in the hilly areas of central Sichuan. A very significant linear positive correlation between the nitrogen nutrient index (NNI) and nitrogen concentration in the aboveground tissues was detected. Based on this, we calculated the nitrogen concentration (Nt) for an NNI equal to 1 at different maize growth stages in both cultivars and observed that the Nt value can be used as a reference index for nitrogen nutrition diagnosis. Additionally, we found a highly significant quadratic convex function relationship between the NNI (y) and the nitrogen fertilizer level (x). The following regression equations were derived for these maize cultivars with the data obtained from each growth period along five consecutive years (2011–2015): yZH 311 = − 0.000005x2 + 0.003074x + 0.553206 (R2 = 0.5432**) and yXY 508 = − 0.000004x2 + 0.002914x + 0.512555 (R2 = 0.6279**). For an NNI value equal to 1, the nitrogen application level required was 224.07 kg·hm−2 for ZH 311 and 283.01 kg·hm−2 for XY 508, indicating that the suitable application rate for the nitrogen-efficient cultivar is lower than that for the nitrogen-inefficient cultivar. Our experimental data reinforce the concept that selecting nitrogen-efficient maize cultivars is an effective technical measure to reduce nitrogen input needs and increase nitrogen use efficiency during maize production.

Effects of multifunctional plant rhizosphere promoting bacteria on maize growth in black soil areas in Northeast China

The application of microbial fertilizer plays an important role in improving soil restoration and fertilizer utilization. The effects of microbial fertilizer are greatly affected by crop genotypes and ecological conditions. Little is known about the effects of microbial fertilizers on maize production in Northeast China. To develop microbial fertilizer specific to the black soil and the climate characteristics of Northeast China, we isolated five plant rhizosphere-promoting bacteria (PGPR), named as MZ1, MZ2, MZ3, MZ4 and MZ5, with different degrees of biological functions such as IAA synthesis, phosphate-solubilizing, potassium-solubilizing and siderophore-releasing, from the rhizosphere of maize field. The analysis of ecological adaptability showed that those five strains differed in salt resistance, drought tolerance, acid and alkali resistance, pesticide resistance. The 16S rRNA gene sequences analysis showed that the strains MZ1, MZ2, MZ3, MZ4 and MZ5 belonged to the genus of Sphingomonas, Enterobacter, Pseudomonas, Bacillus and Rhizobium, respectively. In maize field experiment with 50% nitrogen fertilizer reduction, the inoculation with MZ1, MZ3 and MZ5 increased grain yield by 19.9%-25.0%. MZ1, MZ3, and MZ5 could be used as microbial fertilizers for maize in Northeast China.

Effectiveness of Melaleuca cajuputi Biochar as a Leaching Loss for Nitrogen Fertilizer and Intercropping in Maize

Background: Biochar has a function for soil amendment and leaching loss for nitrogen fertilizer. The objectives of this study was to evaluate the effectiveness of Melaleuca cajuputi biochar as a leaching loss for nitrogen fertilizer and intercropping in maize. Methods: The study was conducted from February to June 2019 in Menggoran Forest Resort, Playen District, Gunungkidul Regency, Special Province of Yogyakarta, Indonesia. The experimental design was a randomized complete block design (RCBD) factorial with three replications as the response surface methodology (RSM). The treatments consisted of biochar levels made from Melaleuca cajuputi waste (0, 5, 10, 15 tons ha-1) and nitrogen fertilizer levels sourced from urea (0, 150, 300 kg ha-1) as independent variables. The observation parameters were nitrate reductase activity (NRA), total chlorophyll (TC), net photosynthesis (NP), nitrogen loss (NL), nitrogen use efficiency (NUE) and seed yield per hectare (SY). Result: The RSM revealed that the optimum value of 13.290 tons ha-1 of Melaleuca cajuputi biochar (MCB) and 245.350 kg ha-1 of nitrogen fertilizer (NF) can reduced urea by 18.22%. This recommendation increased NRA, TC, NP, NL, NUE and SY by 35.28%, 19.55%, 18.09%, -46.81%, 27.96% and 61.78%, respectively, in compare to the single application of urea.

Response of Watermelon Pulp (Citrullus colocynthoides) to Intercropped Maize (Zea mays L.) With Plants Distributions Under Different Nitrogen Fertilization Levels

Two field experiments were carried out at the Experimental Farm of Gemmeiza Agriculture Research Station, Agricultural Research Center (ARC), Egypt after 2018 and 2019 summer growing seasons to determine the effect of intercropping pattern of yellow maize hybrid (single cross 168: &amp;ldquo;SC 168&amp;rdquo;) with watermelon pulp at three plant distributions (20 cm between hills and one plant/hill, 40 cm between hills and two plants/hill and 60 cm between hills and three plants/hill) and different levels of nitrogen fertilizer (25, 50, 75 and 100% of the recommended dose &amp;ldquo;120 kg N fad-1&amp;rdquo;) as well as their interactions on maize and watermelon pulp growth, yield and its attributes as well as competitive relationships and yield advantages. The experiments were carried out in split-plot design with four replicates. The main-plots were assigned to plant distributions of maize, the sub-plots were allocated to levels of nitrogen fertilizer for maize. The obtained results showed that planting maize plants on one side of terraces of 140 cm width with 20 cm between hills and leaving one plant/hill and planting watermelon pulp on the other side of the terraces produced the highest values of plant height, ear height, number of kernels row-1, 100-kernel weight and grain yield fad-1, at the same time the lowest values of ear leaf area, ear length, ear diameter and number of rows ear-1 of maize as well as the lowest values of growth, yield and its attributes of watermelon pulp during the both seasons. Mineral fertilizing maize plants with 75% of the recommended dose (90 kg N/fad) and watermelon pulp with the recommended dose produced the highest values of all studied growth characters, yield and its attributes of maize and watermelon pulp in both seasons. The highest values of land equivalent ratio (LER), relative crowding coefficient (RCC), area time equivalent ratio (ATER), land equivalent coefficient (LEC), aggressivity index (AI), monetary advantage index (MAI), actual yield (L.E.) of watermelon, Total income (L.E.) and economic return (L.E.) were obtained from planting maize plants on one side of terraces of 140 cm width with 60 cm between hills and leaving three plants/hill and planting watermelon pulp on the other side of the terraces besides fertilizing maize plants with 75% of the recommended dose (90 kg N/fad) and watermelon pulp with the recommended dose in both seasons. It can be recommended that planting maize on 60 cm between hills and leaving three plants/hill and planting watermelon pulp on the other side of the terraces besides fertilizing maize plants with 90 kg N/fad and watermelon pulp with the recommended dose to obtain the maximum values growth, yield and its attributes of watermelon pulp and competitive relationships and yield advantages of both crops under the climates conditions of Middle Delta, Egypt.

Assessment and Prevention Strategies of Soil Surface Crusting Caused by Rainfall Events: Case Study of Sebeya Catchment Agricultural Land in Rwanda

The history of soil erosion is an integral part of the agriculture. All over the world, wherever human being started the agricultural operations, there exists the problem of soil erosion in some extent. Soil erosion leads to the reduction of water infiltration rate and enhances runoff and soil degradation. This study focuses on Sebeya catchment located in the Western part of Rwanda. The main objective of this study was to assess various preventive measures against soil surface crusting and development of runoff coefficients in order to minimize the soil loss in Sebeya catchment agricultural fields. The proposed methodology was much concerned with the efficiency analysis of soil conservation practice of mulching in maize cover crops. The names of the three experimental field plots sited are Maize-Fertilizer-Mulching (MFM), Maize-Fertilizer (MF) and Bare Soil (BS) which were set in Rugerero Sector of Rubavu District. Each of these 3 plots was constructed with its runoff collecting tank and they were under similar conditions except land cover. Samples of soil from field plots and water from runoff collecting tanks were tested for soil classification and soil loss estimation from each plot respectively. The analysis of results showed that soil of the experimental plots is a gravelly sand with (sand:56.27%; clay and silt: 3.24% and gravel: 40.49%). Also, the results showed that the plot coded as MFM, has high moisture content with low runoff and soil loss compared to 2 other plots. This research revealed that soil conservation practices such as surface mulching and vegetative cover reduce runoff, soil loss and are well recommended for preventing and controlling soil surface crusting.&#x0D; Keywords: Soil erosion, mulching, soil crusting, field experiments, Rwanda

Effects of nitrogen supply methods on fate of nitrogen in maize under alternate partial root-zone irrigation

Partial root-zone irrigation (PRI) has been practiced worldwide, but little information is available on nitrogen (N) supply methods influence on fate of applied N fertilizer for crop production under PRI. A field experiment was conducted to investigate effect of N supply methods on the uptake, residual, and loss of applied N fertilizer in maize (Zea mays L.) under alternate PRI at Wuwei, northwest China in 2014. 15N-labeled urea was used as N fertilizer. Two irrigation methods included alternate furrow irrigation (AI) and conventional furrow irrigation (CI). Two N fertilizer supply methods included conventional N supply (CN) and alternate N supply (AN), were applied in combination with each irrigation method. Grain yield, root length density (RLD), N uptake by maize at the maturity stage, and atom % of 15N excess, residual 15N and residual NO3-N in the 0-100 cm soil layer after maize harvest were determined. Results shown that compared to CI coupled with CN, AI coupled with AN or CN significantly increased the grain yield, harvest index, RLD, N uptake by maize, 15N accumulation in grain, atom % of 15N excess in the 0-60 cm soil layer, the residual 15N and 15N uptake rates; but significantly decreased the residual NO3-N in the 0-100 cm soil layers and 15N loss rate. Moreover, the synchronized rather than separation supply of N fertilizer and water enhanced the most above parameters under AI. 15N uptake rate was positively correlated with RLD in the 0-40 cm soil layer, suggesting that the enhanced RLD contributed to the improved 15N uptake rate. Therefore, alternate furrow irrigation coupled with conventional or alternate nitrogen supply (synchronized supply of N fertilizer and water) could help improve 15N uptake rate and reduce the 15N loss rate. Keywords: 15N-labeled technology, root length density, nitrogen fertilizer fate, nitrogen management, residual nitrogen DOI: 10.25165/j.ijabe.20201303.5287 Citation: Qi D L, Hu T T, Song X. Effects of nitrogen supply methods on fate of nitrogen in maize under alternate partial root-zone irrigation. Int J Agric & Biol Eng, 2020; 13(3): 129–135.

Maize ZmPT7 regulates Pi uptake and redistribution which is modulated by phosphorylation.

SummaryPhosphorus, an essential mineral macronutrient, is a major constituent of fertilizers for maize (Zea mays L.) production. However, the molecular mechanisms of phosphate (Pi) acquisition in maize plants and its redistribution remain unclear. This study presents the functional characterization of ZmPT7 in Pi uptake and redistribution in maize. The ZmPT7 was expressed in roots and leaves, and induced during Pi starvation. The ZmPT7 complemented the Pi‐uptake deficiency of yeast mutant phoΔnull and Arabidopsis mutant pht1;1Δ4Δ, indicating that ZmPT7 functioned as a Pi transporter. We generated zmpt7 mutants by CRISPR/Cas9 and ZmPT7‐overexpressing lines. The zmpt7 mutants showed reduced, whereas the ZmPT7‐overexpressing lines displayed increased Pi‐uptake capacity and Pi redistribution from old to young leaves, demonstrating that ZmPT7 played central roles in Pi acquisition and Pi redistribution from old to young leaves. The ZmCK2 kinases phosphorylated ZmPT7 at Ser‐521 in old maize leaves, which enhanced transport activity of ZmPT7. The Ser‐520 of Arabidopsis AtPHT1;1, a conserved residue of ZmPT7 Ser‐521, was also phosphorylated by AtCK2 kinase, and the mutation of Ser‐520 to Glu (phosphorylation mimic) yielded enhanced transport activity of AtPHT1;1. Taken together, these results indicate that ZmPT7 plays important roles in Pi acquisition and redistribution, and its transport activity is modulated by phosphorylation.

Ammonia Volatilization Reduced by Combined Application of Biogas Slurry and Chemical Fertilizer in Maize–Wheat Rotation System in North China Plain

Digestate and biogas slurry (BS) are the byproduct of biogas engineering that could be used for elevating plant growth. However, the consequent emissions of ammonia from BS are considered a severe threat to the atmosphere. Herein, we conducted two consecutive field experiments with wheat–maize rotations to find out the optimum ratio of BS to combine with chemical fertilizer (CF) to reduce ammonia volatilization (AV) while keeping the stable crop yield. In maize season, 226.5 kg N/ha of CF was applied. In wheat season, 226.5 kg N/ha was applied at different ratios (100%, 80%, and 50%) between BS and CF. Our results found that the maximum yield of 6250 kg/ha was produced by CF, and this yield could be obtained through a combined application of 38% BS mixed with CF. Highest AV produced of 16.08 kg/ha by CF. BS treatments significantly reduced the emission from 18% to 32% in comparison to CF. The combined application of BS-CF produced the highest yield due to essential nutrients coming from both BS-CF. Subsequently, it reduced the AV depending on fertilizer type and fertilizer rate. An optimal ratio of 38% BS was recommended to produce the highest yield and lowest ammonia emissions. The application of BS together with different ratios of CF could be an alternative agricultural strategy to obtain desired crop yield and reduce AV in North China Plain (NCP).