• Authors:
    • Ranamukhaarachchi, S.
    • Thongsaga, K.
  • Source: Asia-Pacific Journal of Rural Development
  • Volume: 19
  • Issue: 1
  • Year: 2009
  • Summary: Water stress is unpredictable in rain-fed agriculture, and regularly affects maize production in Thailand. This study was conducted to determine the effect of 10-day dry period occurring during critical growth stages on growth and yield of maize, and to simulate and compare the performance using CERES-Maize model in DSSAT version 4.0.2.0 using concurrent weather data. Two popular maize hybrids, namely Suwan 4452 and Pacific 224, were subjected to four 10-day dry periods [viz. 36-45 days from seeding (DFS), 46-55 DFS, 56-65 DFS, and 66-75 DFS] as treatments together with a control grown with regular irrigation in a split plot design with four replicates. The experiment was conducted during the longest dry period, from December 2006 to April 2007, under controlled irrigation. Soil moisture content at 0-15 cm and 15-30 cm depths reached near the lower limit of readily available water (RAW) in six days, after the cessation of irrigation, which declined to near permanent wilting point (PWP), but did not reach PWP during the 10-day period. Leaf area index (LAI) (ranged from 4.3 to 4.6), plant height (ranged from 2.2 to 2.4 m) and biomass (ranged from 6.8 to 7.6 t/ha) at silking were not significantly affected by the 10-day suspension of irrigation, but various differences were observed in the plant height: Suwan 4452 was taller than Pacific 224. Number of grains per ear, 100-grain weight, grain yield and the harvest index remained unaffected due to the 10-day suspension of irrigation, but were significantly greater in Pacific 224 than Suwan 4452. CERES-Maize model showed excellent results in predicting time to silking, LAI and biomass at silking, 100-grain weight, grain yield and the harvest index. However, some deviations were found in Suwan variety for LAI and 100-grain weight, and of Pacific 224 in the time to silking. Comparisons showed that simulations were very much close, except for the cases noted. The model simulated responses similar to the actual values in this study.
  • Authors:
    • Thu, K.
  • Source: Culture & Agriculture
  • Volume: 31
  • Issue: 1
  • Year: 2009
  • Summary: This special issue is a commentary on Richard Manning's book entitled "Against the Grain: How Agriculture Has Hijacked Civilization". The thesis of his book is that agriculture occupies a central role in human civilization and that sustaining American culture requires fundamental shifts in food production, distribution and preferences. The issue consists of six articles. The first article presents comments of a panel of anthropologists and Manning's response and discusses recent developments in the production of maize for fuel ethanol in the midwestern United States. The second article examines Richard Manning's book with critical attention to the role of agriculture, technology, and population as agents of cultural evolutionary change. It also attends to the critical role of agriculture and the food system in contemporary issues of sustainability and social justice. The third article focuses on those dimensions of Manning's book that deal with the relationship between the consolidation of agriculture and the centralization of political power. The fourth article provides a summary comment of Manning's encounter with the anthropologists who read and commented on his book. The fifth article explores biotechnology transfer and genetically modified organisms as "public goods" for Colombia. The sixth article explores the role of gender, cultural change, and market dynamics affecting the resilience of adaptive livelihoods in arid landscapes in Northern Peru for families who lack access to irrigation and rely on goat herding in a context of cyclical droughts.
  • Authors:
    • Andreotti, M.
    • Benett, C. G. S.
    • Buzetti, S.
    • Valderrama, M.
    • Arf, O.
    • Sa, M. E. de
  • Source: Pesquisa Agropecuaria Tropical
  • Volume: 39
  • Issue: 3
  • Year: 2009
  • Summary: The objective of this study was to evaluate the effect of doses and sources of nitrogen and phosphorus, on the production components and grain yield, on irrigated common beans cultivated in a Cerrado area of Selviria, Mato Grosso do Sul State, Brazil (20degrees22′S, 51degrees22′W, altitude 335 m). The experimental design was a randomized block, with 4 doses of top-dressed N (0 kg ha -1, 40 kg ha -1, 80 kg ha -1, and 120 kg ha -1) and 2 sources (urea and coated urea), and 4 doses of phosphorus (0 kg ha -1, 50 kg ha -1, 100 kg ha -1, and 150 kg ha -1 of P 2O 5) and 2 sources (triple super phosphate and coated triple super phosphate), at sowing, with 4 repetitions. Nitrogen and phosphorus content in leaves, pod/plant number, grain/plant number, mass of 100 grains, and grain yield were evaluated. The sources of N, as well as the sources of P 2O 5, did not differ, as related to the number of pods per plant, grains per plant, mass of 100 grains, and grain yield. The doses of N influenced linearly the leaf N content, as well as the grain yield. The doses of P increased linearly the leaf P content and the grain yield, up to the 120 kg ha ′1 dose.
  • Authors:
    • Gomes, A. da S.
    • Vernetti Junior, F. de J.
    • Schuch, L. O. B.
  • Source: Revista Brasileira de Agrociencia
  • Volume: 15
  • Issue: 1/4
  • Year: 2009
  • Summary: In the state of Rio Grande do Sul, Brazil, there are 5,5 million ha of tilled plain soils that have been partly cropped with irrigated rice ( Oryza sativa L.), the remainder area lodging extensive beef cattle raising. This research was undertaken aiming chiefly to identify one or more technical solutions to the agribusiness associated with the agro-ecosystem of the "Temperate Climate region". The work was carried out at experimental area of Lowland Agricultural Research Station of Embrapa Temperate Climate (31degrees 52′S; 52degrees 21′24W), Brazil. The experiment was planned in a split-plot randomized blocks design with three replications and performed along ten years. The treatments were successive winter and spring-summer crops growing during five years, followed by two years of no-cropping and then three years of irrigated rice crop growing. The spring-summer crops were corn and soybean, besides rice; the winter crops were poaceae (Ps), fabaceae (Fs), species mixtures (Ms), turnip (T) and native grass species (NG). Seeding was performed either by no-ploughing (PD) or conventional (SC). Grain and dry-matter yields were estimated and evaluated. The evaluations were performed by analysis of variance (F and Duncan tests). The results allowed the following conclusions: (1) Ps and Fs had the highest yields; (2) corn yields were higher when its crop followed Fs species and/or Ms; (3) corn crop in tiled plains shows better performance when planted in no-plow; (4) soybean crop following Ps performed better than following Fs; (5) no-plough favors the soybean crop in tilled plains; (6) irrigated rice yields are higher succeeding the corn crop.
  • Authors:
    • Mazurana, M.
    • Debiasi, H.
    • Trein, C.
    • Levien, R.
    • Conte, O.
  • Source: Ciencia Rural
  • Volume: 39
  • Issue: 4
  • Year: 2009
  • Summary: This study evaluates the effect of machine traffic, soil mobilization, soil cover by crop residues and water supply on corn under no tillage on a Paleudult. Machine traffic intensity, working depth of driller shank furrow opener for fertilizer deposition and amount of residues covering the soil surface, with and without irrigation, were evaluated. The experimental design used was split plot, with 36 plots being 18 with irrigation and 18 without irrigation. The treatments were quantities (0, 2, 4, 5, 6 and 8 Mg ha -1) of black oats ( Avena strigosa) and vetch ( Vicia sativa) residues, two driller shank depths for fertilizer deposition (6 and 12 cm) and traffic machine conditions (tractor and combine) in a triple factorial design with three replicates. Corn was sowed in 12/10/2005, using 62.000 seeds per hectare. A basal dressing of NPK 5-20-20 was applied at a rate of 400 kg ha -1. Two top dressing nitrogen applications were performed, totalizing 180 kg ha -1 of N. Corn grain yield, plant population and root dry matter were evaluated. Corn yield and plant population were influenced by presence or absence of irrigation. None of the above parameters were modified by working depth of driller shank furrow opener for fertilizer deposition. Wheel traffic conditions affected corn yield and plant population.
  • Authors:
    • Lawson, A. R.
    • Greenwood, K. L.
    • Kelly, K. B.
  • Source: Agricultural Water Management
  • Volume: 96
  • Issue: 5
  • Year: 2009
  • Summary: Knowledge of the components of the water balance - evaporation, transpiration and deep drainage - would be beneficial for targeting productivity improvements for irrigated forages in northern Victoria. We aimed to estimate these components using a simple water balance and the dual crop coefficients provided in FAO-56. Soil water deficits from a field experiment, comparing the water use of six border-check and one spray irrigated forage system, agreed well with the modelled values, except for alfalfa where irrigation intake was restricted. About 85% of the water applied to perennial forages (perennial ryegrass/white clover, tall fescue/white clover and alfalfa) was used for transpiration, 10% for evaporation and 5% was lost as drainage below the root zone. Evaporation was highest from the double-cropped (oats/millet) system (30%) and was 5-25% of the water used by winter-growing annual pastures (Persian clover/Italian ryegrass and both border-check and spray irrigated subterranean clover/Italian ryegrass). The high proportion of water used as transpiration by the perennial forages was due to their high ground cover maintained throughout the year. When compared over similar seasonal conditions, actively growing forages used similar amounts of water, indicating that any increases in water productivity will be mainly due to higher production and/or to matching the growing season of the forage to periods of lower potential evapotranspiration.
  • Authors:
    • Nagaki, M.
    • Ke, F.
  • Source: Agricultural Information Research
  • Volume: 18
  • Issue: 2
  • Year: 2009
  • Summary: In the arid areas of Northwest China, agriculture especially crop farming consumes most of water resource. Water-intensive and low value-added wheat is cultivated as a staple food of the local people in large scale. Because of the surface water scarcity, irrigation mainly depends on pumping the groundwater in these areas. Based on field surveys conducted in 2005 and 2006 both in the south and the north of Minqin County, Gansu province, this study is designed to study the role of groundwater irrigation on wheat production and how to improve the technical efficiencies (TEs) of wheat farmers by estimating a Stochastic Frontier Production Function (SFPF). The above information is valuable for how to save wheat water consumption and improving the food safety in the arid areas. The empirical results showed that expenditure on pumping groundwater played important role in wheat production. Meanwhile, the same expenditure played more effectively on wheat intercropping with maize in the south than that in the north. As a result, the farmers in the south are more likely to increase expenditures on pumping water than the farmers in the north. Therefore, the government should make new program to restrict wheat water consumption and to secure the farmers in both areas to use the groundwater fairly. Meanwhile, it is suggested that younger farmers can achieve a higher TE both in the south and the north. For the input-intensive intercropping in the south, a larger family, higher education of the farm managers, and coordination of their part-time jobs with agricultural production activities can also help to get higher TEs.
  • Authors:
    • Bahrani, M.
    • Ahmadi, M.
  • Source: American-Eurasian Journal of Agricultural and Environmental Science
  • Volume: 5
  • Issue: 6
  • Year: 2009
  • Summary: Irrigated rapeseed ( Brassica napus L.) cultivation is currently expanding in rotation with winter cereals in Iran where its reproductive growth is often exposed to water deficit in many parts, particularly in the south. A two growing seasons (2006-2008) field experiment was conducted at the Experimental Research Center, Shiraz University to study the effects of water stress at different growth stages [Normal irrigation at all growth stages (control), water stress at flowering, at pod development and at seed filling stages] and nitrogen (N) levels (0, 75, 150 and 225 kg ha -1) on yield and yield components of rapeseed (Telayeh cultivar). The design was split plots arranged in randomized complete block with four replications. Full irrigation and the highest N level had the highest plant height, number of branches per plant, pods per plant, seed and oil yields. However, increased N levels decreased seed oil content and had no significant effect on 1000-seed weight. Flowering was the most sensitive stage for water stress damage resulting a drastic reduction in seed and oil yields by 29.5% and 31.7%, respectively. Pods per plants was the most sensitive yield components to water stress during reproductive growth in both year and it had the highest significant positive correlation with seed and biological yields. The seed and oil yields of the 1st season were more than the 2nd season due to favorable weather conditions for growth. Overall, supplying sufficient water to rapeseed crop, particularly at flowering and pod formation, in comparison with 225 kg ha -1 of N fertilizer are important to produce higher yields.
  • Authors:
    • Komjathy, L.
    • Nemenyi, A.
    • Helyes, L.
    • Pek, Z.
    • Bocs, A.
  • Source: Cereal Research Communications
  • Volume: 37
  • Issue: Suppl. 1
  • Year: 2009
  • Summary: Tomato is one of the most extensively cultivated horticultural crops in the world. Water supply is important for yield quantity and quality. The aim of the present study is to evaluate the canopy temperature and the yield on processing tomato substances with different water supply. There were two treatments, one of them was the irrigated plant material which got 333 mm water, including the precipitation and the other was the cut off substance which means the watering was stopped at the beginning of the ripening process, there was a control as well which got 189 mm precipitation. The canopy temperature was measured row by row with a Raytek MX 4 type infrared thermometer. The stomatal conductance was measured by AP4 type porometer. There were significant differences between the control and irrigated plants according to the water supply which was formulated the canopy values. The plants with a deficient water supply were decreased the transpiration rate, therefore its cooling effect didn't show up. The permanently irrigated tomato plants' yield exceeded the unirrigated ones with almost 50%. It is emerged from the study that the irrigation has a positive effect on the amount of the harvestable yield. It's came from the regression analysis that over a specific amount of water (285 mm), the ripened yield is affected negatively.
  • Authors:
    • Kovacs, I.
    • Lantos, C.
    • Pauk, J.
    • Cseuz, L.
  • Source: Cereal Research Communications
  • Volume: 37
  • Issue: Suppl. 1
  • Year: 2009
  • Summary: Drought tolerance of wheat was tested by a mobile automatic rain shelter (MARS) in a conventional pedigree breeding program of Cereal Research Non-Profit Ltd. Co. (CRC) in Szeged. The MARS, parallel with ideal water supply gives a good chance for field testing of relatively high number of genotypes for drought tolerance. Using the automatic rain shelter which was installed in 2006, advanced lines of winter wheat could be tested for tolerance to water shortages under irrigated (control treatment) and under dry conditions. Withdrawal of water caused significant effects on yield and yield components and raised the canopy temperature of the genotypes tested. We have developed a novel breeding system by which we can routinely select for drought resistance. The methods applied can easily be incorporated into our working pedigree breeding system.