Variation In Maize Yield Research Articles

Economic efficiency of maize production in Yola North Local Government area of Adamawa State, Nigeria

This paper presents empirical evidence on the input-output relationship and the efficiency of resource use in maize production in Yola North Local Government Area of Adamawa state. A simple random sampling technique was employed and 120 maize farmers were selected from a population of 364. Data were analyzed using regression model. The production function analysis in the form of Cobb-Douglass production function was found very suitable for the analysis hence was selected as the best fit. The results showed that three of the inputs namely, fertilizer, seed and land were statistically significant at ñ . 0.05 and 85% of the variation in maize yield was accounted for by the inputs included in the model. Similarly, the efficiency ratio computed showed that land, seed and fertilizer had MVP/MFC ratio greater than unity implying that the inputs were underutilized and output could be increased by increasing the levels of their utilization. The elasticity of production was greater than 1.00 which implied increasing return to scale. Finally, the study observed that the problems faced by maize farmers were, financial constraints, poor land tenure system, inadequate fertilizer, unavailability of extension service and improved seed.Key word: Elasticity, marginal value product, marginal factor cost, input-output.

Delineation of site-specific management units in a saline region at the Venice Lagoon margin, Italy, using soil reflectance and apparent electrical conductivity

Site-specific crop management utilizes site-specific management units (SSMUs) to apply inputs when, where, and in the amount needed to increase food productivity, optimize resource utilization, increase profitability, and reduce detrimental environmental impacts. It is the objective of this study to demonstrate the delineation of SSMUs using geospatial apparent soil electrical conductivity (ECa) and bare-soil reflectance measurements. The study site was a 21-ha field at the southern margin of the Venice Lagoon, Italy, which is known to have considerable spatial variability of soil properties influencing crop yield. Maize (Zea mais L.) yield maps from 2010 and 2011 showed high spatial heterogeneity primarily due to variation in soil-related factors. Approximately 53% of the spatial variation in maize yield was successfully modeled according to the variability of four soil properties: salinity, texture, organic carbon content, and bulk density. The spatial variability of these soil properties was characterized by the combined use of intensive geospatial ECa measurements and bare-soil normalized difference vegetation index (NDVI) survey data. On the basis of the relationships with these soil properties, ECa and NDVI were used to divide the field into five SSMUs using fuzzy c-means clustering: one homogeneous with optimal maize yield, one unit affected by high soil salinity, one characterized by very coarse texture (i.e., sandy paleochannels), and two zones with both soil salinity and high organic carbon content. Yield monitoring maps provide valuable spatial information, but do not provide reasons for the variation in yield. However, even in cases where measurements like ECa and bare-soil NDVI are not directly correlated to maize yield, their combined use can help classify the soil according to its fertility. The identification of areas where soil properties are fairly homogeneous can help managing diverse soil-related issues optimizing resource use, lowering costs, and increasing soil quality.

Spatial Adaptabilities of Spring Maize to Variation of Climatic Conditions

ABSTRACTEnvironmental conditions have important effects on maize (Zea mays L.) growth. To examine spatial variation in maize yield and aboveground biomass and to understand differences in the response of maize yield and aboveground biomass to climatic factors under various ecological conditions, we conducted experiments from 2007 to 2010 at 34 locations in seven provinces in the spring maize region of northern China between 35°11′ N lat and 48°08′ N lat. We used a most widely cultivated maize hybrid ZD958. The maize yield and aboveground biomass (presilking and postsilking) were found to be strongly influenced by locations. A nonlinear relationship existed between the maize yields and latitude. Maize yield was the greatest (12.19 Mg ha–1) at 39°08′ N lat, and the corresponding presilking and postsilking aboveground biomass at this location were 143.41 and 215.35 g per plant, respectively. Variations in the harvest index (HI) and 1000‐kernel weight were the main reasons for yield latitudinal trends. Among the climatic factors, air temperature had the best relationships with variations in maize yield, HI, and 1000‐kernel weight. With latitudes increasing northward, presilking aboveground biomass affected by growth duration length and accumulated solar radiation increased significantly. The aboveground biomass of postsilking stage that was affected by the maximum temperature, daily mean temperature, and growing degree days decreased significantly with latitudes increasing northward. However, there were no significant changes of total aboveground biomass with latitudes increasing northward.

Identificação e quantificação do efeito de fatores ambientais na produtividade da cultura do milho na região de janaúba, mg

In semiarid region of Minas Gerais State, Brazil, there is a large deficit on maize supply, even for family livelihood. Understanding factors that affect maize yield is crucial to develop appropriate crop management strategies. The study aimed at to identifying climatic factors that affect maize yield in Janauba, MG, Brazil, and quantify the degree of influence of climate elements by using crop yield data simulated with CSM-CERES-Maize model. The model was used to simulate maize yield sowed weekly throughout the year, under irrigated and rainfed conditions, from 1977 to 2008. Statistical analysis performed on simulated yield data indicated that the factors sowing date, year and irrigation (rainfed and irrigated) and their double interactions were significant at a 5% level. The water availability accounted for the greatest amount of total maize yield variation in the study region (61.9%), followed by sowing date and its second order interactions (26.2%). Under optimal water availability conditions (irrigated), the factors that most influence the yield of maize are, basically, the air temperature and solar radiation variations. This fact was evidenced by low productivity values found in years that the incident solar radiation was below the observed average.

Goat manure application improves phosphate fertilizer effectiveness through enhanced biological cycling of phosphorus

High phosphate fixation necessitates the application of high rates of phosphorus (P) fertilizers to achieve reasonable crop yields in most tropical soils. The present study investigated the efficacy of goat manure in improving the effectiveness of fertilizer P for increasing maize yields. Treatments consisted of combinations of four rates of goat manure (0, 2.5, 5 and 10 g kg)−1 equivalent to 0, 5, 10 and 20 t goat manure ha)−1, respectively) and four rates of inorganic P (0, 45, 90 and 180 mg P kg)−1 equivalent to 0, 90, 180 and 360 kg P ha)−1, respectively) applied to 7 kg soil in pots. Maize (Zea maize L.) was sown immediately after application. Maize dry matter yields (maize yield) and the concentrations of resin P, soil microbial biomass P (biomass P), 0.5 mol L)−1 NaHCO3 extractable inorganic P (NaHCO3-Pi) and 0.1 mol L)−1 NaOH extractable inorganic P (NaOH-Pi) were determined 6 and 12 weeks after planting. After 12 weeks, maize yield increased with the addition of fertilizer P or goat manure separately and was further increased when they were applied together. These synergistic effects on maize yield were ascribed to enhanced P cycling because goat manure increased the concentration of biomass P, which in turn accounted for most of the observed variations (63%) in maize yield. The combination of biomass P and resin P, however, explained a greater proportion of the variations in maize yield (73%), suggesting that the usefulness of biomass P as an index of P availability would be enhanced if used in conjunction with resin P. These results indicated that goat manure application could be used to increase soil microbial biomass P, which in turn could improve the effectiveness of fertilizer P in the Eastern Cape, South Africa.

Effects of tree shading on maize crop within a Poplar-maize compound system in Hexi Corridor oasis, northwestern China

Effects of tree shading on crop within agroforestry system in the oasis regions or under irrigation agriculture are poorly understood. Objective was to determine maize yield variation and its reasons when tall Poplar trees (Populus gansuensis) were grown in western and eastern margins of the crop field in Hexi Corridor desert oasis in northwestern China. Maize growing among the 50 m alley space were divided into five regions, including shading region in western side (W-S), non-shading region in western side (W-NS), middle region (M), shading region in eastern side (E-S) and non-shading region in eastern side (E-NS), for all measurements. Measurements of leaf area expansion were carried from seeding to flowering stage, photosynthetic physiological parameters and microclimate characteristics were measured at booting stage, grain yield and other harvest parameters were obtained at harvest time. We found that tree shading reduced the crop yield by 27 and 22% in western and eastern regions, respectively, and also, mean crop yield for western side was 23% lower than eastern side. The direct reason of yield variation was transpiration rate (E) variation at booting stage, that is, maize which had higher daily mean E would obtained higher yield. Moreover, changes of incident photosynthetically active radiation (PARi), air temperature (T a) and CO2 concentration (C a) were the basic reasons of yield variation among different regions. Because higher PARi, higher T a and lower C a, which caused by the tree shading, would all led to higher E and finally higher crop yield.

Participatory assessment of soil degradation in the uplands of southwestern Tanzania: Implications for sustainable agriculture and rural livelihoods

Rural household food insecurity and poverty are closely linked to soil degradation in Sub-Saharan Africa. However, causes, degradation processes, coping strategies and need for interventions may vary from one place to another. This study was conducted in Mbinga District, SW Tanzania, to investigate causes and biophysical processes of soil degradation; effects on livelihoods, coping strategies and entry points for interventions. Implications for sustainable production and rural livelihoods are discussed. Participatory Rural Appraisal (PRA), household surveys using a short open-ended questionnaire and biophysical exploration were the research tools used. Soil fertility depletion resulting from continuous cropping and erosion losses is the main form of soil degradation. Maize yield was 57% lower in fertility-depleted farms than in productive farms. Soil pH, Ca2+, Mg2+ and CEC accounted for 79% of variations in maize yield. Organic soil fertility amelioration was a common strategy used by smallholders. Use of beneficial tree and shrub fallows is the most environmentally, economically and socially promising improvement that can be used to build on the existing strengths of farmers' knowledge and strategies. Subsidy for the right type of fertilizers, infrastructure improvement and education of farmers on proper use of fertilizers should significantly contribute to improved and sustainable production and livelihoods.

Wheat and maize yield variations in the Brod-Posavina area

In general, wheat and maize yields in the Brod-Posavina County (BPC) were about 15% lower (10-year means 1981–1990) in comparison with their yields in the region. Wheat yield variations in the region among the years were higher in comparison with maize yield. For example, the highest yield of wheat and maize were higher than the lowest yield for 61% and 34%, respectively. Analogic comparison for Slav. Brod and N. Gradiska municipalities were 78% and 41% (wheat), as well as 41% and 24% (maize), respectively. In the last 8-year period, mean wheat yields in the region were for 17% lower and maize yield for 4% higher in comparison with mean yields of 80ies. These differences in level of BPC were 10% lower and 12% higher, for wheat and maize, respectively. We presume that low or absence effects of tile drainage because of their inadequate servicing could be expalantion for wheat yield decreasing. The lower yields of wheat are mainly in connection with oversupplies of water. However, low maize yields are in connection with water shortage and the higher air-temperatures. Low supplies of P and K are additional factors of low yields of field crops in the hydromorhic soils of the BPC.

Physico-chemical properties and productivity of two tropical soils amended with dehydrated swine waste

With maize ( Zea mays L.) as the productivity indicator crop, the fertilizing value of dehydrated swine waste (DSW) was assessed on two texturally contrasting tropical soils, a sandy Kandic Paleustult (S l) and a clayey Lithic Usorthent (S 2). The treatments were different rates of DSW and inorganic fertilizer (F): 0%; 2·5%; 2·5% + F; 5·0%; 5·0% + F; 7·5%; 7·5% + F; 10·0%; 10·0% + F; and F alone. The F treatment consisted of the locally recommended rates of N, P, K and Mg for maize production. On both soils, high rates of DSW (⩾ 5·0%) delayed maize germination. Maize height and dry-matter yield increased with DSW rates, with the highest yield obtained at the 10·0% + F treatment. On all treatments, yield was consistently better on the more fertile S 2 than on the S 1 soil. All treatments including DSW out-performed the F-alone treatment because of higher nutrient contents of the organic waste-amended soils. The amounts of N, P, K, Ca and Mg released during the study explained individually between 66 and 73% of variation in maize yield on both soils. The C:N ratio of the treatments had an indirect effect on maize performance, explaining between 91 and 95% of the variation in yield. Increasing rates of DSW progressively increased the soil pH, organic carbon, N, P, exchangeable Ca, Mg, K and CEC, and reduced the exchangeable acidity at the end of the experiment. Also, the moisture retention capacity of both soils increased at all matric potentials between 0 and − 1500 kpa following DSW application. Even though the water-dispersible clay increased slightly with high DSW rates (implying reduced stability at the colloidal level), the overall effect of the organic amendment was towards enhanced resistance of the macro aggregates to disruptive water forces. Improvement in these physico-chemical properties was a direct consequence of increased organic matter levels following the DSW application to the soils.

CJ89-52. Numerical analysis of sheet metal deep-drawing process : By Deng Zhi (Beijing University of Sci. and Tech., Beijing, China) and Chen Hezheng (Beijing Inst. of Aero. and Astro., Beijing, China). Chinese J. Mech. Engng25, No. 4 (Dec. 1989), pp. 33–40

In the context of global climate change, drought has become an important factor that affects the maize yield in China. To analyse the impact of drought on maize yield loss in Northeast China in current and future climate scenarios, the Composite Meteorological Drought Index (CI) is introduced to reconstruct the following drought indicators: drought accumulative days (DAD), drought accumulative intensity (DAI), and consecutive drought days (CDD). These three drought indicators are used to describe the three-dimensional characteristics of drought in this study. Sen’s slope method and three-dimensional copula functions are adopted to analyse the variety of drought features, and Ensemble Empirical Mode Decomposition (EEMD) is used to analyse the variations in maize yield. A temporal assessment of the standardized yield residuals series (SYRS) of maize from 1961 to 2014 is conducted. A panel regression model is applied to demonstrate the drought impact on maize yield at various growth stages under the RCP4.5 scenario. The results show that the drought risk level for midwest Jilin Province, western Liaoning, and eastern Heilongjiang increase with global warming in the current scenario. The shorter three-dimensional joint return periods, 44–80 yr, were mainly located in western Jilin Province, Liaodong Peninsula, and northwestern Liaoning. Eastern Heilongjiang has a slightly longer joint return period of 80–100 yr. The SYRS shows a strong statistical correlation with drought indicator variations; drought-prone regions exhibit strong positive correlations. In comparison, excess precipitation regions show strong negative correlations with drought indicators in most growth stages. Drought indicators have a relatively strong association with SYRS at the milky–mature maize growth stage, and the occurrence of drought during this period primarily determines the maize yield changes in the future. Maize yield changes are −2.04%, −2.65% and −1.57% for Liaoning, Jilin, and Heilongjiang Province under the RCP4.5 scenario. These results can be used as a tool for early warning of drought risk to maize, and will accelerate the progress of drought disaster risk management.

European Corn Borer (Lepidoptera: Pyralidae) Damage to Maize in Eastern North Carolina

Field survey experiments were conducted in 1981, 1982, and 1983 in eastern North Carolina to assess level of damage done by Ostrinia nubilalis (Hubner) to commercial maize. There was a significant relationship between grain weight and cavities per plant in 10 of 12 fields surveyed. In controlled experiments in 1982 and 1983, a more significant relationship was observed between grain weight and cavities per plant. Reduction in maize yield by O. nubilalis ranged from 102.72 to 465.79 kg/ha per cavity. Yield reduction was affected by infestation date, infestation level, and year (rainfall). In these experiments, variation in maize yield accounted for by cavities ranged from 4.1 to 54.3%. Damage potential of O. nubilalis to maize was not significantly different at 49,000 and 69,000 plants per ha.

Soil temperature and its association with maize yield variations in the Highlands of Kenya

summaryIn the Highlands of Kenya every 1-week delay in planting maize after the onset of the rains reduces the grain yield by approximately 0·6 t/ha. No satisfactory explanation has been found for this phenomenon. A physiological growth study was made on four dates of planting per year over 4 years. Early growth rates and maximum crop growth rates showed a progressive decline with delay in planting which resulted in smaller plants at 5 weeks post-emergence and at 50 % tassel emergence in maize planted later. There was a strong relationship between the size of plant at tasselling and the final grain yield and a highly significant relationship (r = 0·94) between the size of plant at 5 weeks post emergence and the final grain yield. Other environmental studies showed that soil temperature at 7·5 cm, coupled with a soil moisture stress factor, largely controlled the dry-matter production rate during early growth, and consideration of the mean value of these two variables over the first 5 weeks of growth accounted for 70% of the variation of dry matter at 5 weeks post-emergence. It was further shown that 82% of the variation in final grain yield caused by date of planting could be accounted for by consideration of the mean value of these two variables during the first 5 weeks of growth.