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Maize Yields (maize + yield)

Distribution by Scientific Domains

Earth and Environmental Science	77%

Selected Abstracts

Drip Irrigation Frequency: The Effects and Their Interaction with Nitrogen Fertilization on Sandy Soil Water Distribution, Maize Yield and Water Use Efficiency Under Egyptian Conditions

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2008
S. E. El-Hendawy
Abstract Irrigation frequency is one of the most important factors in drip irrigation scheduling that affects the soil water regime, the water and fertilization use efficiency and the crop yield, although the same quantity of water is applied. Therefore, field experiments were conducted for 2 years in the summer season of 2005 and 2006 on sandy soils to investigate the effects of irrigation frequency and their interaction with nitrogen fertilization on water distribution, grain yield, yield components and water use efficiency (WUE) of two white grain maize hybrids (Zea mays L.). The experiment was conducted by using a randomized complete block split-split plot design, with four irrigation frequencies (once every 2, 3, 4 and 5 days), two nitrogen levels (190 and 380 kg N ha,1), and two maize hybrids (three-way cross 310 and single cross 10) as the main-plot, split-plot, and split-split plot treatments respectively. The results indicate that drip irrigation frequency did affect soil water content and retained soil water, depending on soil depth. Grain yield with the application of 190 kg N ha,1 was not statistically different from that at 380 kg N ha,1 at the irrigation frequency once every 5 days. However, the application of 190 kg N ha,1 resulted in a significant yield reduction of 25 %, 18 % and 9 % in 2005 and 20 %, 13 % and 6 % in 2006 compared with 380 kg N ha,1 at the irrigation frequencies once every 2, 3 and 4 days respectively. The response function between yield components and irrigation frequency treatments was quadratic in both growing seasons except for 100-grain weight, where the function was linear. WUE increased with increasing irrigation frequency and nitrogen levels, and reached the maximum values at once every 2 and 3 days and at 380 kg N ha,1. In order to improve the WUE and grain yield for drip-irrigated maize in sandy soils, it is recommended that irrigation frequency should be once every 2 or 3 days at the investigated nitrogen levels of 380 kg N ha,1 regardless of maize varieties. However, further optimization with a reduced nitrogen application rate should be aimed at and will have to be investigated. [source]

Maize Yields as Affected by Short- and Long-Term Improved Fallows: A Comparative Analysis in the Asian Humid Tropics

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 6 2005
R. Schelbert
Abstract Improved short- or long-term fallows are considered suitable low external input technologies for maintaining productivity and sustainability of tropical smallholder upland cropping units, although comparisons on the benefits of this technology are not widely reported. A field study evaluated the impact of improved short (6 months) and long-term fallow (18 months) using Crotalaria juncea and Tithonia diversifolia, in relation to a natural fallow of the same durations, on the productivity of maize (Zea mays), the most important upland cereal in tropical Asia, over a minor season. The use of improved fallows, especially Tithonia, increased maize yields over the Crotalaria or natural fallow. While the overall yields of maize after a long fallow were greater, the beneficial impact of the green manures was significantly higher in the short fallows. The causal factors for this trend, including biomass production of the improved fallows and possible impact on soils, along with the greater benefits of short-term fallows for increasing maize yields in the tropics due to lower requirements of unproductive time are presented. [source]

Better land husbandry in Honduras: towards the new paradigm in conserving soil, water and productivity

LAND DEGRADATION AND DEVELOPMENT, Issue 3 2002
J. Hellin
Abstract Land shortages are forcing more smallholder farmers to cultivate tropical steeplands. Resulting accelerated soil erosion is being countered by the promotion of soil conservation (SC) technologies, such as cross-slope barriers, which aim to reduce soil loss and preserve land productivity. However, farmer adoption rates tend to be low. This is often attributed to the farmers' conservatism or lack of education. Research in Honduras's steeplands demonstrates that farmers value SC, provided that it promotes agricultural production. Field research from 1995,98, involving farmed test plots on slopes greater than 35 per cent (19 degrees), demonstrates that at least one typical SC technology,live barriers of Vetiveria zizanioides (vetiver grass),has little or no impact on maize yield. This means that farmers see little benefit from their investment in the SC method. They find that erratic rainfall, pests and diseases and a lack of economic resources are far greater threats to their livelihoods than soil erosion. Consequently, SC has a low priority. Keeping soil in place avoids major off-farm disbenefits. However, the SC technique tested here made no discernible difference to slope foot sediment yields during the life of this study. In sum, a new approach is needed. Promoting ,Better Land Husbandry' strategies, which seek to combine farmers' concerns about productivity with conservationists' concerns about reducing soil erosion,often via cover-management,seem to be the best way forward. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Effects of selection for resistance to Sesamia nonagrioides on maize yield, performance and stability under infestation with Sesamia nonagrioides and Ostrinia nubilalis in Spain

ANNALS OF APPLIED BIOLOGY, Issue 3 2010
G. Sandoya
A maize synthetic population was improved for resistance to the Mediterranean corn borer (MCB, Sesamia nonagrioides) while maintaining yield. The objectives of this research were to investigate whether yield and yield stability of the maize synthetic population named EPS12 were affected by selection for MCB resistance; also to determine which genotypic and environmental covariates could explain the genotype (G), environment (E) and genotype × environment (GE) effects for yield under corn borer infestation. Plants from three cycles of selection and their testcrosses to three inbred testers (A639, B93 and EP42) were evaluated at two locations in 2 years, under MCB and European corn borer infestations. After selection EPS12 was a more stable genotype. Hybrids derived from crosses between B93 and inbreds obtained from the initial cycles of selection could be recommended for cultivation in northern Spain. The yield of crosses between cycles of selection and testers increased when there were fewer days with temperatures >25°C and higher mean maximum temperatures. Differences in yield among these genotypes were mostly explained by resistance to corn borer attack. In general, among EPS12-derived materials, genetic characteristics that contribute to increased grain yield were also responsible for increased abiotic stress tolerance. [source]

Narrow rows reduce biomass and seed production of weeds and increase maize yield

ANNALS OF APPLIED BIOLOGY, Issue 2 2009
A.B. Mashingaidze
Abstract Smallholder farmers in southern African countries rely primarily on cultural control and hoe weeding to combat weeds, but often times, they are unable to keep up with the weeding requirements of the crop because of its laboriousness, causing them to incur major yield losses. Optimisation of crop planting pattern could help to increase yield and suppress weeds and to reduce the critical period of weed control and the weeding requirements to attain maximum yield. Experiments were carried out in Zimbabwe during two growing seasons to assess the effect of maize density and spatial arrangement on crop yield, growth and seed production of weeds and to determine the critical period for weeding. Planting maize at 60 cm row distance achieved higher yields and better weed suppression than planting at 75 or 90 cm row distance. Increasing crop densities beyond the customary three to four plants m,2 gave modest reductions in weed biomass but also diminished crop yields, probably because of increased competition for water and nutrient resources. Maize planted in narrow rows (60 cm) intercepted more radiation and suffered less yield reduction from delaying hoe weeding than those planted in wider rows (75 or 90 cm), and the duration of the weed-free period required to attain maximum grain yield was 3 weeks shorter in the narrow spacing than that in the 75- and 90-cm row spacings. Weeding was more effective in curtailing weed seed production in the narrow row spatial arrangements than in the wide row planting. The results of these studies show that narrow row spacings may reduce weeding requirements and increase yields. [source]

Maize Yields as Affected by Short- and Long-Term Improved Fallows: A Comparative Analysis in the Asian Humid Tropics

Cropping strategies, soil fertility investment and land management practices by smallholder farmers in communal and resettlement areas in Zimbabwe

LAND DEGRADATION AND DEVELOPMENT, Issue 5 2009
J. G. Cobo
Abstract Three smallholder villages located in typical communal (from 1948), old (1987) and new (2002) resettlement areas, on loamy sand, sandy loam and clay soils, respectively, were selected to explore differences on natural resource management and land productivity. Focus group discussions and surveys were carried out with farmers. Additionally, farmers in three wealth classes per village were chosen for a detailed assessment of their main production systems. Maize grain yields (t,ha,1) in the communal (1·5,4·0) and new resettlement areas (1·9,4·3) were similar but significantly higher than in the old resettlement area (0·9,2·7), despite lower soil quality in the communal area. Nutrient input use was the main factor controlling maize productivity in the three areas (R2,=,59,83%), while soil quality accounted for up to 12%. Partial N balances (kg,ha,1,yr,1) were significantly lower in the new resettlement (,9·1 to +14·3) and old resettlement (+7·4 to +9·6) than in the communal area (+2·1 to +59·6) due to lower nutrient applications. Averaged P balances were usually negative. Consistently, maize yields, nutrient applications and partial N balances were higher in the high wealth class than in poorer classes. This study found that most farmers in the new resettlement area were exploiting the inherent soil nutrient stocks more than farmers in the other two areas. We argue that effective policies supporting an efficient fertilizer distribution and improved soil management practices, with clearer rights to land, are necessary to avoid future land degradation and to improve food security in Zimbabwe, particularly in the resettlement areas. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Temporal changes of resource use, soil fertility and economic situation in upland Northwest Vietnam

LAND DEGRADATION AND DEVELOPMENT, Issue 1 2002
A. Wezel
Abstract Agricultural land in lowland Vietnam is scarce due to population growth. Hence, cultivation is increasingly practised on the steep upland slopes. Factors affecting resource use, soil fertility and household economics were studied in six villages of the Black Thai ethnic group in northwest Vietnam. Farmers were interviewed about their individual household situation. Yield development of major crops and cropping patterns in upland cultivation over the last 50 years were recorded in group discussions. In addition, soil fertility was analysed on different land-use units. Formerly predominant upland rice changed to maize and cassava production at present. Decreasing soil fertility and a shift from subsistence to market-oriented production, facilitated by new maize varieties and better access to markets are major causes. The Black Thai farmers economy has improved in recent years. The decline in soil fertility is concealed by higher maize yields from new varieties, and soil fertility conservation ranks low among farmers' priorities. The improved economy of the individual households might be of short duration if farmers cannot be sensitized to new resource management options. These have to be developed in line with farmers' priorities and the fragile environment of Vietnam's uplands. Copyright © 2002 John Wiley & Sons, Ltd. [source]