DETERMINING THE EFFICIENCY OF NITROGEN FERTILIZERS ON MAIZE USING ISOTOPE METHODS AT DIFFERENT IRRIGATION LEVELS

Field experiments were conducted in a sandy loam soil at the research farm of the Indian Agricultural Research Institute (IARI), New Delhi during the kharif season of 2012 and 2013 with the objective to study the effect of crop residue mulch, irrigation and nitrogen (N) on soil water dynamics, growth, yield, water and N use efficiency of maize. Maize (cv. HQPM 1) was grown in a split-split plot design with two levels of irrigation, two levels of mulch and three levels of N. The grain yield of maize increased significantly by 31 per cent under irrigated condition than that of rainfed condition in the year 2012. Application of crop residue mulch increased the grain yield of maize significantly by 11.5 and 28.4 per cent compared to nomulch treatment in 2012 and 2013, respectively. Application of N significantly increased the grain yield of maize over the control. However, there was no significant difference between 75 kg and 150 kg N ha−1 with respect to grain and biomass yield of maize. The water use efficiency of maize increased significantly by 12.6 and 36 per cent in 2012 and 2013, respectively due to crop residue mulch. The apparent N recovery and agronomic N use efficiency increased significantly but physiological N use efficiency decreased under mulching. So, maize may be grown with 75 kg N ha−1 and wheat residue mulch @ 10 t ha−1 to achieve higher yield, water use efficiency and N use efficiency in Upper-Indo-Gangetic Plain region.

Crops adapted to semi‐arid conditions enhance forage supply amid water scarcity. This study aimed to compare six forage cactus clones (Orelha de Elefante Mexicana [OEM , Opuntia stricta (Haw.) Haw.]; Orelha de Elefante Africana [OEA, Opuntia undulata Griffiths]; V19, Opuntia larreyi F.A.C. Weber ex Coult.; F8, Opuntia atropes Rose; MIUDA (MIU) and IPA‐Sertânia (IPA), Nopalea cochenillifera (L.) Salm‐Dyck) in terms of morphophysiological traits, forage production, nutrient and water use efficiency, and economic viability under irrigation in a semi‐arid environment. The experiment was conducted from December 2016 to September 2022 in randomised blocks, with treatments of six clones: OEM, OEA, V19, F8, MIU and IPA, with three replicates. Phenology, morphophysiological rates, cutting time, productivity, water balance, water and nutrient use efficiency and crop economic indicators were determined. Plant tissue analyses were carried out to determine concentrations, coefficient of biological utilisation (CBU) and nutrient use efficiency (NUE). The OEM exhibited the highest annual average fresh matter yield (300 Mg ha −1 year −1 ) and dry matter yield (24 Mg ha −1 year −1 ). The efficiencies of water productivity, net and gross economic productivity of the total water applied to the system, and irrigation varied depending on the clone and cycle. The CBU of all nutrients showed an inverse relationship with cladode nutrient concentrations. This indicates that the CBU increased as the nutrient concentration in plant tissues decreased across all clones analysed. The OEM clone showed the highest NUE for all nutrients. OEM was more productive and had higher water and nutrient use efficiencies. Furthermore, the MIU clone showed superior economic efficiency in irrigation water use.

Increasing planting density is an important ways to increase maize yield. A hot topic of conversation in the current research is how to improve crop light efficiency and yield potential by optimizing the cultivation mode under high density planting is a hot topic in current research. Thus, in this study, a field experiment was conducted to explore the effects of stereo-planting patterns on water and the utilization light resource and maize yields. Planting patterns included the conventional flat planting pattern (as the control, CK) and the stereo-planting in ridge and furrow (T). Each planting pattern had three planting densities, i.e., 60,000 plants ha−1 (D1), 75,000 plants ha−1 (D2) and 90,000 plants ha−1 (D3). The results showed that stereo-planting affected the physiological characteristics of plants by changing the spatial distribution of soil moisture. At the silking stage (R1), photosynthetic rate (Pn) of plants on the ridge was similar to CK, and transpiration rate (Tr) was significantly lower than that of CK. Pn of maize in the furrow was significantly higher than that of CK, and Tr was similar to CK. Stereoscopic planting had different effects on intraspecific competition intensity in maize population in different growing stages. In the six-leaf stage (V6), stereo-planting increased competition intensity of maize on the ridge, but lowered that of maize in the furrow by affecting the spatial distribution of soil moisture. During the R1 stage, stereo-planting increased the light transmittance rate within the canopy and eased the plant’s competition for light by reducing plant height and leaf area of maize under three density conditions. Stereo-planting had no effect on grain yield and dry matter accumulation of ridge-planted maize in the later growing stage, but it did increased the dry matter accumulation and grain yield of furrow-planted maize due to the improvement of the light environment and photosynthetic characteristics of the population. In two test years, stereo-planting increased 5.0–11.0% average yield of maize compared to CK under three density conditions. These results indicate that stereo-planting can reduce the plant’s competition for light and water resources and improve its physiological traits of plant by optimizing its spatial distribution of soil moisture and canopy structure, thus further increasing grain yield of maize under high-density planting conditions.

Abstract. The adoption of Conservation agriculture (CA) contributes to sustainable production and its advantages include lower inputs and stable yields. This study was conducted in the research field of Regional Agricultural Research Station, Bhagetada, Dipayal, Doti during 2014 and 2015 to identify the effect of CA on grain yield and income of maize in Maize based cropping system. Both conservation and conventional agricultural (ConvA) practices were evaluated on two maize based cropping systems namely maize-wheat-mungbean (M-W-MB) and maize-lentil-mungbean (M-L-MB). For this purpose two maize varieties namely Raj Kumar and Arun-2 were used. The average productivity of maize under M-L-MB cropping system was 1.6% higher (5.75 t/ha) than M-W-MB cropping system (5.66 t/ha). The average grain yield of maize under CA was 16.7% higher (6.15 t/ha) than ConvA (5.27 t/ha). Rajkumar produced 43% higher average grain yield (6.73 t/ha) than Arun-2 variety (4.69 t/ha). The average net benefit was slightly higher (US$ 597.33/ha) under M-L-MB cropping system than M-W-MB cropping system (US$ 573.89/ha). Similarly, the average net benefit from CA was 102% higher (US$ 783.67/ha) than ConvA (US$ 386.79/ha). Rajkumar variety gave 127% higher average net benefit (US$ 813.49/ha) than Arun-2 (US$ 357.81/ha). The average benefit - cost (B:C) ratio of M-L-MB cropping system was slightly higher (1.72) than the average B:C ratio of M-W-MB cropping system (1.70). The average B:C ratio of CA was 42% higher (2.01) than ConvA (1.41). The average B:C ratio of Rajkumar variety was found 33% higher (1.95) than Arun-2 (1.46). The higher grain yield, net profit and B:C ratio were found in CA practices under M-L-MB cropping system and Rajkumar variety. This study suggests that hybrid maize planting and the adoption of M-L-MB cropping system should be used to increase grain yield and economic performance under CA practices.

A trial was conducted to determine the effects of crop rotation with N-P rates on grain yield of maize and soil fertility in Bako over a period of five years. The experiment was laid out in a randomized complete block design in factorial arrangement with rotation crops (Niger seed, haricot bean and tef) as main factor and two levels of NP fertilizers ( half recommended (55/23 kg N-P2O5 ha-1 and recommended (110/46 kg N-P2O5 ha-1) rate as sub factor and continuous maize with three replications. Higher mean grain yield of maize was recorded from maize following rotation crops with recommended rate of fertilizer compared to continuous maize. Maize following rotation crops gave mean grain yield advantage of 640 to 830 and 1921 to 1968 kg ha-1 compared to continuous maize at half and full recommended N-P fertilizer rate. Maize following Niger seed produced mean grain yield advantage of 971 and 1527 kg ha-1 compared to haricot bean and tef. Primary nutrient (N, P and K) composition of the tissue and grain of maize were significantly higher with maize following rotation crop compared to continuous maize, indicting the enhancement of the nutrient use efficiency of maize following rotation crops. Crop rotation with fertilizer amendment improved the pH of the soil. Crop rotation and N-P amendment enabled maize yields and soil fertility to be maintained at a higher level. Multiple advantages accrue from the use of crop rotation. Higher grain yield and high net return of maize were realized following Niger seed, haricot bean and tef compared to continuous maize. Maize following Niger seed followed by haricot bean with the recommended rate of fertilizer is a better management option for sustainable maize production in Western Oromia. Keywords: Crop Rotation; Niger Seed; N-P Rate

Background:Though nitrogen and water are key factors for tomato production, their optimum integration is not well identified in the study area. Therefore, optimizing irrigation level and nitrogen fertilizer rates are crucial to boost tomato yield as well as for better nutrient and Water Use Efficiency (WUE).Objective:The objective of the present study was to determine the optimum irrigation water and nitrogen fertilizer levels for higher tomato yield, improved water and nutrient use efficiencies.Methods:Split plot design was implemented with three irrigation levels expressed as a percentage of potential Evapotranspiration (ETc) allotted to the main plots and four nitrogen levels as sub-plots. Climate data were imported to AquaCrop model climate dataset for determining irrigation water amount and irrigation scheduling. Irrigation scheduling was determined using the FAO AquaCrop model and the crop evapotranspiration (ETc) in AquaCrop model was determined using Penman-Monteith method.Results:Irrigation water and nitrogen fertilizer levels markedly influenced the growth and yield performance of tomato, nutrient residue, Agronomic Efficiency (AE), Partial Factor Productivity (PFP) as well as Water Use Efficiency (WUE). With this, the most influential factor for tomato production was the nitrogen level rather than irrigation.Conclusion:In this study, higher growth and yield performance as well as, better water and nutrient use efficiencies of tomato were obtained while the irrigation level of 75% ETc is interacted with a nitrogen fertilizer rate of 92 kg N/ha.

Effect of nitrogen-sulphur nutrition and inhibitors of nitrification on the yield and quality of maize grain

Maize is among the most important cereal crops in Ethiopia. Intercropping results in high overall system productivity on a given piece of land due to efficient use of the available plant growth resources. Field experiment was conducted to were to evaluate and select the cropping systems and best performing common bean varieties in intercropping with maize at jejebicho research station for higher productivity and profitability in southern parts of Ethiopia, under Wondo genet Agricultural Research Center at Sankura wereda, Jejebicho research station in 2019/20 cropping season. Three varieties of common bean (Deme, KAT-B1 and Awash-2) and were intercropped with two maize varieties (Limu and Shone). The three common bean varieties and two maize varieties were included as a sole for comparison. Randomized complete block design in factorial with three replications was used. Aboveground biomass, days to tasseling, hundred kernel weight, grain yield and harvest index of maize were significantly affected by varieties of common bean, cropping system was also significantly affected leaf area, leaf index, days to tasseling, days to physiological maturity and grain yield of maize but their interaction effect were non significantly affected. Days to tasseling of maize were delayed (81.50 days) and hastened (74.23 days) by variety Awash-2 and Deme, respectively as compared to KAT-B1. The wider leaf area (910.20cm²) was measured from intercropped maize than sole and the larger leaf area index (3.79) was also recorded from intercropped maize than sole one. Days to tasseling of maize were delayed (80.80 days) at sole cropped of maize. The longer days to physiological maturity (143.84 days) of maize was taken from sole cropping of maize. The highest grain yield (7.60 ton/ha) of maize was taken from Shone intercropped with Awash-2 as compared to varieties. In cropping system, the maximum grain yield (7.12 ton/ha) of maize was obtained from intercropped of it. Plant height, branch number per plant, number of seed per pod, number of pod per plant, days to physiological maturity, aboveground biomass, hundred kernel weight, grain yield and harvest index of common bean. The longest plant (132.13cm) was measured from Deme intercropped with Limu. The highest (5.17) number of branches was counted at Deme intercropped with Limu. The highest number of pods per plant and number of seed per pod (10.92 and 4.63) was counted at Deme intercropped with Limu and Limu with Awash-2 respectively. The highest grain yield (22.38 ton/ha) was obtained when Shone intercropped with Deme. The highest partial land equivalent ratio (LER) of maize and common bean non significantly affected by varieties of both. Monitory advantage index was also non significantly affected. However, the highest value of monetary advantage index (105,359 ETB ha^-1) was obtained at Shone intercropped with Deme. Therefore, any of the two (Limu or Shone) maize varieties could be recommended for intercropping with Deme of common bean variety.

Maize is among the most important cereal crops in Ethiopia. Rely-intercropping of mung bean between maize enable to get grain yield of maize instead sole alone. Field experiment was conducted to assess the effects of relay intercropping mung bean at different population density and row arrangements with maize yield components and yield of the component crops, to evaluate the productivity and economic value of maize-mung bean intercropping at Sankura Wereda Jejebicho research station in 2019-2021 main cropping season. Three spatial row arrangements (1:1, 1:2 and 1:3) with four population densities (PD) (25%, 50%, 75% and 100%) were intercropped with maize variety ‘Shone’. Each of the component crops were included as a sole for comparison. Randomized complete block design in factorial with three replications was used. days to tasselling, days to physiological maturity, leaf area, leaf area index, hundred kernel weight, grain yield and harvest index of maize significantly affected by the interaction effects of population density and spatial arrangements of mung bean. The highest (8.19 ton/ha) grain yield of maize was obtained from 100% population density and 1:3 spatial row arrangement of mung bean. This may due to the presence of high interspecific competition with related high plant population density per plot area compared to other treatments. Whereas the highest grain yield mung bean (18.54 Quintal/ha) was obtained from when mung rely intercropped with 100% population density and 1:3 row arrangements. The highest thousand seed weight (42.18g) was recorded from 25% population density and 1:1 row arrangements of mung bean. The maximum Land equivalent ration value was calculated from 1.88 from 100% population density in 2019 cropping season. The highest monitory advantage index value 110,280 Ethiopian birr) was obtained from 100% population density with all the three spatial row arrangement of mung bean. Therefore, this experiment could be recommended for mung bean rely cropped with maize by 100% population density and 1:3 row arrangement able the famers to get better grain yield of maize as well as mung bean.

Effects of nitrogen application rates and irrigation regimes on grain yield and water use efficiency of maize under alternate partial root-zone irrigation

Chapter 1: Nutrient use efficiency in plants: an overview.- Part I: Nutrients as a Key Driver of Nutrient Use Efficiency.- Chapter 2: Soils and Inputs Management Options for Increasing Nutrient Use Efficiency.- Chapter 3: Nutrient and water use efficiency in soil: The influence of geological mineral amendments.- Chapter 4: Resource conserving techniques for improving nitrogen use-efficiency.- Chapter 5: Strategies for enhancing phosphorus efficiency in crop production systems.- Chapter 6: Efficiency of soil and fertilizer phosphorus use in time: a comparison between recovered struvite, FePO4-sludge, digestate, animal manure and synthetic fertilizer.- Chapter 7: Strategies for Enhancing Zinc Efficiency in Crop Plants.- Chapter 8: Nitrification inhibitors: classes and its use in nitrification management.- Part-II: Microbiological aspects of Nutrient Use Efficiency.- Chapter 9: Role of Microorganisms in Plant Nutrition and Health.- Chapter 10: Role of Cyanobacteria in Nutrient Cycle and Use Efficiency in the Soil.- Chapter 11: Trichoderma improves nutrient use efficiency in crop plants.- Chapter 12: Bio-priming mediated nutrient use efficiency of crop species.- Chapter 13: Unrealized potential of seed biopriming for versatile agriculture.- Part-III: Molecular and physiological aspects of Nutrient Use Efficiency.- Chapter 14: Improving nutrient use efficiency by exploiting genetic diversity of crops.- Chapter 15: Micro RNA based approach to improve nitrogen use efficiency in plants.- Chapter 16: Biofortification for selecting and developing crop cultivars denser in iron and zinc.- Chapter 17: Understanding genetic and molecular bases of Fe and Zn accumulation towards development of micronutrient enriched maize.- Part-IV: Nutrient Use Efficiency of Crop Species.- Chapter 18: Nitrogen uptake and use efficiency in rice.- Chapter 19: Nutrient-use efficiency in Sorghum.- Chapter 20: Improving nutrient use efficiency in oilseeds Brassica.- Chapter 21: Strategies for higher nutrient use efficiency and productivity in forage crops.- Chapter 22: Integrated nutrient management in potato for increasing nutrient use efficiency and sustainable productivity.- Part-V: Specialised Case Studies.- Chapter 23: Enhancing Nutrient Use Efficiencies in Rainfed Systems.- Chapter 24: Dynamics Of Plant Nutrients, Utilization And Uptake, And Soil Microbial Community In Crops Under Ambient And Elevated Carbon Dioxide.- Chapter 25: Phytometallophore Mediated Nutrient Acquisition by Plants.

A field experiment was carried out at AICRP on Weed Management Research Farm, Department of Agronomy, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during kharif 2020-21. Fertigation is the technique of supplying dissolved fertilizers to crops through an irrigation system.The experiment was laid out in split plot design with three replications and twenty treatment combinations having four different fertigation levels and five weed management practices. The results revealed that, significantly maximum grain yield of rice (5103 kgha-1), straw yield (7268 kgha-1) and harvest index (41.25%) were found maximum at 125% RDNK level of fertigation in 5 splits than lower fertigation levels (75 and 100 per cent) and over conventional soil application of 100 per cent RDF. Nutrient use efficiency (NUE) was found better in lower drip fertigation level of75 per cent recommended dose of N and K per ha as compared to conventional soil application of fertilizers. Among the herbicides, directed spray of Pretilachlor + Pyrazosulfuron Ethyl @ 0.615 a.i. kgha-1 PE fb. Bispyribac sodium @ 0.025 a.i kgha-1 at 25 DAS resulted in maximum rice grain yield (5231 kgha-1) and also total nutrient uptake by crop and water use efficiency indicating the feasibility of using herbicides for effective weed management in rice and for enhancing NUE and WUE. The 125% RDNK through drip fertigation in 5 splits recorded maximum Gross Monetary returns (₹120353 ha-1), Net Monetary Returns (₹72924) and B:C ratio (2.54), nutrient use efficiency and water use efficiency.The herbicidal treatment of Pretilachlor + Pyrazosulfuron Ethyl0.615 kgha-1 PE fb. Bispyribac sodium 0.025 kgha-1 at 25 DAS registered maximum GMR (₹128755 ha-1), NMR (₹81412ha-1) and B:C ratio (2.72) among all herbicidal treatments, indicating the feasibility of using herbicides for effective weed management in rice.

Grain yield and water use efficiency of maize as influenced by different irrigation regimes through sprinkler irrigation under temperate climate

To explore the effects of different densities of mixed-cropping on 13C-photosynthate distribution and grain yield of maize, we measured photosynthetic characteristics, 13C-photosynthate distribution, dry matter accumulation, and grain yield under different planting densities (LD, 67500 plants·hm-2 and HD, 97500 plants·hm-2) under mixed-cropping (M, 1:1, 2:2) and monoculture of Zhengdan958 (ZD) and Denghai605 (DH). The results showed that with the increases of planting density, grain yield, 13C-photosynthate allocation to grain, dry matter accumulation, and leaf area index (LAI) increased, but the chlorophyll content and net photosynthetic rate decreased. No significant difference was observed between the monoculture and mixed-cropping at the density of 67500 plants·hm-2. However, at 97500 plants·hm-2, LAI, chlorophyll content, net photosynthetic rate and dry matter accumulation in mixed-cropping were higher than that in monoculture. Mixed-cropping promoted the transport of dry matter from the vegetative organs such as stem to the grain and the distribution of 13C-photosynthates to grain. Grain yield of summer maize significantly increased in mixed-cropping due to the increase of 1000-grain mass. Under high plant density, the mixed-cropping could enlarge photosynthetic area, maintain higher net photosynthetic rate, increase dry matter accumulation, improve the distribution of dry matter, promote the distribution of 13C-photosynthates to grains and thus increase the grain yield. Our results indicated that mixed-cropping could significantly increase the yield of close planting summer maize in Huang-Huai-Hai Plain.

A lysimeter study was carried out in the Department of Agricultural Chemistry and Soil Science at Rajasthan College of Agriculture, Udaipur. The treatments comprized of two texturally different soils (sandy loam and clay loam), four RSC levels (0.0, 2.5, 5.0 and 7.5 m moles L-1) in irrigation water and two flowering annuals (marigold and chrysanthemum) making 16 treatment combinations in factorial completely randomized design in triplicate. The ECe, organic carbon, water soluble Ca2+, Mg2+, K+, Na+, Cl- and SO4- and exchangeable Ca2+, Mg2+, K+ and SAR decreased, while the pH, water soluble CO3- and HCO3-, exchangeable Na+ and ESP increased with rise in RSC level in irrigation water. A significantly low soluble Ca2+, Mg2+ and HCO3- contents and higher values of soluble SO4- and exchangeable K+ were observed in the soil with marigold. A higher accumulation of Mg2+, K+ and exchangeable K+ was recorded in sandy loam soil, while higher values of exchangeable Ca2+, Mg2+ and Na+ were recorded in clay loam soil. Dry matter yield per lysimeter registered a decrease with an increase in RSC levels in irrigation water from 0.0 to 7.5 m moles L-1. The reduction in dry matter yield was more pronounced in clay loam soil as compared to sandy loam soil. The content of N in flowering annuals increased with an increase in the RSC level in irrigation water, whereas the contents of P, K Cu, Fe, Mn and Zn showed a decrease with an increase in RSC levels in irrigation water from 0.0 to 7.5 m moles L-1. Further, a higher content of N, P, Cu, Mn, and Zn was recorded for marigold. Key words: Residual sodium carbonate, marigold, chrysanthemum, nutrient content.