• Authors:
    • Fora, G. C.
    • Solomonesc, A.
    • Moatar, M.
    • Chisalita, I.
    • Stefan, C.
    • Olaru, D.
  • Source: Journal of Horticulture, Forestry and Biotechnology
  • Volume: 16
  • Issue: 2
  • Year: 2012
  • Summary: From planting to emergence, the range is over 30 days (the potato 18-25 days). During this period must be destroyed weeds and crust can form especially on heavy land and wet weather. The best results are obtained when the works are done as soon as weeds appear. The first work is performed at 10-14 days after planting. When planting was done on rising land, harrow ground working-net, the aggregate of three fields, the working width of 8.4 m and a forward speed of 5.7 km/h, harrows destroy the weeds and crust rising land ridge, and the interval between rising land. After 1-4 days working again, this time with thinning type cultivator equipped with tracks. To destroy weeds and crust in the area of rising land and by restoring them, cover and choke the weeds that tend to rise. Successive work-net harrow and cultivator parts such rarity, recovery Billon, repeats again (when they planted tuber sprouting) or 2 times to other cultures, after intervals of 8-12 days.
  • Authors:
    • Martin, E. C.
    • Subramani, J.
  • Source: Applied Engineering in Agriculture
  • Volume: 28
  • Issue: 1
  • Year: 2012
  • Summary: In 2001, the Arizona Department of Water Resources implemented an agricultural Best Management Practice (BMP) program. The program was designed to encourage the use of BMPs in irrigation with the goal of increasing the efficient use of water resources on the farm. Several BMPs were identified through meetings with stakeholders, researchers, and scientists. One of the BMPs identified was alternate furrow irrigation. This three-year study was designed to determine the impact of alternate furrow irrigation on surface irrigation water applications and cotton yield. There were two treatments, every furrow (EF) and every other furrow (EOF). Lint yields were 1794 and 1694 kg/ha in 2006; 1795 and 1902 kg/ha in 2007; and 1365 and 1237 kg/ha in 2008 for the EF and EOF treatments, respectively. Seasonal irrigation water applications were 187.7 and 162.3 cm in 2006; 151.4 and 137.2 cm in 2007; and 184.1 and 132.6 cm in 2008 for EF and EOF treatments, respectively. The results indicate that an average of 30.5 cm of water can be saved by the implementation of an alternate furrow irrigation scheme without significantly reducing lint yield.
  • Authors:
    • Taalimoghaddam, A.
    • Karbasi, A.
  • Source: Annals of Biological Research
  • Volume: 3
  • Issue: 7
  • Year: 2012
  • Summary: In this study, two goals are pursued. The first, will be addressed the relationship between game theory and linear programming and then, the application of game theory is checked for crops Khorasan Razavi province. Actually, this is a theory that is related to decide when two or more than two competitors compete in a rational. In this study, game theory model is used for the province's major crops include irrigated wheat, rain fed wheat, irrigated barley, rain fed barley, irrigated sugar beet and irrigated cotton. The data included time series of gross product values of the investigated crops for the period 2000-2009. In this study, in game theory have been used the "Wald" decision-making criterion to determine the highest income under the worst conditions. The pattern results Show irrigated sugar beet cultivation is risky product for the period studied. Irrigated sugar beet is included in the optimization program since it will be the highest expected income in the worst conditions. On the other hand, it has the highest coefficient of variation compared to the other crops. As a result, the game theory model is a good indicator for selecting alternative management strategies for farmers.
  • Authors:
    • Gu, X. X.
    • Wang, F. X.
    • Tao, L. J.
  • Source: Chinese Journal of Eco-Agriculture
  • Volume: 20
  • Issue: 3
  • Year: 2012
  • Summary: A pot experiment was conducted in a greenhouse to compare the influences of flood (F) and drip (D) irrigations on soil concentrations of CO 2 and CH 4 during potato cropping season using the static opaque chamber and gas chromatography technique. Two agronomic measures were evaluated for each irrigation regime under mulched (M) and non-mulched conditions. Three more treatments were set under mulched drip irrigation (MD) based on different wet ratio ( P) - P1 ( P=25%), P2 ( P=33%) and P3 ( P=50%). There were six treatments altogether, denoted as DP1, MDP1, MDP2, MDP3, FC and MF. Bare soils with (MBS) and without (BS) plastic film mulching were set as control treatments. Results suggested that mulching treatments increased soil CO 2 concentration by 10.4%-94.5% due to plastic film mulching increasing effect on temperature and moisture, and barrier effects on natural air transmission of the soil-atmosphere system. Mulching treatments decreased soil CH4 concentration by 5.1%-47.4%. Because of dry-wet alternation under drip-irrigation and decreased soil aeration under flood irrigation, CO 2 concentration was 7.4%-49.7% higher under flood irrigation and CH 4 concentration 6.6%-68.2% lower under drip irrigation. Soil moisture influenced greenhouse gas emission by altering soil aeration and soil dissolved organic matter. The higher the wet ratio under MD, the lower was CO 2 concentration. However, the effect of wet ratio on CH 4 concentration was not clear. Soil temperature was the main driving factor of soil respiration, which also regulated CH 4 oxidation processes. The greenhouse gas concentration in soils after DP1 irrigation showed a significant positive correlation between soil temperature and soil CO 2 concentration. Also after DP1 irrigation, a significant negative correlation existed between soil temperature and soil CH 4 concentration while a significant negative correlation was noted between soil CO 2 and CH 4 concentrations.
  • Authors:
    • Sidhu, B. S.
    • Singh, S.
    • Aujla, M. S.
    • Buttar, G. S.
    • Thind, H. S.
  • Source: Archives of Agronomy and Soil Science
  • Volume: 58
  • Issue: 2
  • Year: 2012
  • Summary: Field experiments were conducted for two years to find out the appropriate sowing configuration and rate of nitrogen (N) for sustained yield and improved water use efficiency of hybrid Bt cotton irrigated through surface drip irrigation. Drip irrigation under normal sowing, in which equal quantities of water and N were applied as check-basin irrigation, resulted in an increase of 389 and 155 kg ha(-1) in seed cotton yield compared with check-basin irrigation during the first and second year, respectively. Normal paired row sowing under a drip irrigation system, in which only 50% of irrigation water was applied compared with normal sowing, produced a yield similar to normal sowing under drip irrigation during both years, resulting in 22% higher water use efficiency. Dense paired row sowing under drip irrigation, in which only 75% irrigation water was applied compared with normal sowing, increased the mean seed cotton yield by 5% and water use efficiency by 19%. Decrease in the rate of nitrogen application (from 150 to 75 kg N ha(-1)) caused a decline in seed cotton yield and water use efficiency under all the methods of sowing, but the reverse was true for agronomic efficiency of N.
  • Authors:
    • Wise, J. C.
    • van Timmeren, S.
    • Isaacs, R.
  • Source: Pest Management Science
  • Volume: 68
  • Issue: 4
  • Year: 2012
  • Summary: BACKGROUND: Soil application of systemic neonicotinoid insecticides can provide opportunities for long-term control of insect pests in vineyards, with minimal risk of pesticide drift or worker exposure. This study compared the effectiveness of neonicotinoid insecticides applied via irrigation injection on key early-season and mid-season insect pests of vineyards in the eastern United States. RESULTS: On vines trained to grow on drip irrigation, early-season application of imidacloprid, clothianidin, thiamethoxam and dinotefuran provided high levels of control against the potato leafhopper, Empoasca fabae. Protection of vines against Japanese beetle, Popillia japonica, and grape berry moth, Paralobesia viteana, was also observed after mid-season applications. Efficacy was poor in commercial vineyards when treatments were applied to the soil before irrigation or rain, indicating that vines must be grown with an irrigation system for efficient uptake of the insecticide. CONCLUSIONS: In drip-irrigated vineyards, soil-applied neonicotinoids can be used to provide long residual control of either early-season or mid- to late-season foliage pests of vineyards. This approach can reduce the dependence on foliar-applied insecticides, with associated benefits for non-target exposure to workers and natural enemies.
  • Authors:
    • Jarsjo, J.
    • Tornqvist, R.
  • Source: Water Resources Management
  • Volume: 26
  • Issue: 4
  • Year: 2012
  • Summary: In many semi-arid and arid regions of the world, water saving strategies need to be implemented in the agricultural sector in order to increase the resilience to water scarcity. We investigate basin-scale hydrological impacts of possible irrigation technique improvements, considering extensive cotton fields in the Aral Sea drainage basin (ASDB), Central Asia. We use a distributed hydrologic model that combines basin-scale, calibrated discharge and evapotranspiration quantifications with experimental results of (on-farm) water application needs for different irrigation techniques. This allows for quantification of how return flows contribute to river discharge through coupled groundwater-surface water-systems at the basin scale, under different regional climatic conditions. Results show that an implementation of improved irrigation techniques can yield water savings that increase the discharge to the Aral Sea by between 1 and 6 km(3)/year. Such water savings could contribute to mitigation of the acute water scarcity in the lower ASDB. The basin-scale water savings are about 60% lower than corresponding on-farm reductions in irrigation water application, since water is re-used and, hence, return flows decrease when less water is applied. Spatial analysis of regional differences in climatic conditions shows that implementation of more efficient irrigation systems would result in much larger (up to a factor 4) water savings in the more arid downstream regions than in the colder, upstream mountainous regions.
  • Authors:
    • Stamatiadis, S.
    • Samaras, V.
    • Tsadilas, C.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 43
  • Issue: 1-2
  • Year: 2012
  • Summary: A 2-year field experiment was conducted in central Greece (Platykampos, Larissa) to investigate productivity parameters of cotton under conditions of water stress. A Latin square split-plot design with three replications was used to evaluate the effect of three irrigation levels (250, 350, and 450 mm) and three fertilization rates (60, 110, and 160 kg N ha(-1)), where irrigation level was the whole-plot factor and the fertilizer was the split-plot factor. The results showed that irrigation level had no significant effect on soil chemical properties, but these only changed with fertilizer application. Concentration of soil nitrates increased in proportion to the amount of applied fertilizer in early July. The associated rise in electrical conductivity (EC) was not sufficiently high as to adversely affect salt-tolerant cotton. The soil acidity produced during formation of nitrate was evident by a soil pH decrease of 0.2 units in the high fertilizer application. A great decline of nitrate N and EC and a rise of pH in all treatments in early August indicated rapid N uptake by the crop during the late stage of vegetative growth. In contrast, cotton yield was not affected by the rate of fertilizer application but by the level of irrigation. This is the reason that correlations between soil properties and yield were insignificant in early July and August. It appears that there was sufficient N available to the crop from sources other than fertilizer N (soil-derived N and irrigation N). Preplant soil nitrates were greater than residual nitrates in the second growing season and indicated depletion of soil mineral N pools of the order of 36 kg N ha(-1) in the 0- to 25-cm depth. Significant negative correlations between soil properties and cotton yield appeared only at the end of the season and indicated that depletion of soil mineral N increased with increasing crop N requirement or irrigation level.
  • Authors:
    • Yelledalli, N. A.
    • Upperi, S. N.
  • Source: Environment and Ecology
  • Volume: 30
  • Issue: 1
  • Year: 2012
  • Summary: The experiment was conducted by supplying both organics and inorganics with desi cotton (Laxmi) under limited irrigation in low fertility soil (sandy loam) during 1995. The results indicated significantly higher chlorophyll a (33.1 mg/g FW) and b (19.33 mg/g FW) contents, cotton yield (8.9 q/ha) and cotton stalk yield (20.5 q/ha) were recorded with RDF+FYM+all the micronutrients over rest of the treatments. Similar trend was recorded for cotton yield, with RDF+FYM (7.6 q/ha) and RDF+all micronutrients (8.5 q/ha) over rest of the treatments. Besides, significantly increased yields of cotton and chlorophyll a and b contents were observed with the application of micronutrients individually over only RDF (6.4 q/ha and 22 and 10.8 mg/g FW).
  • Authors:
    • Nogues, I.
    • Michelozzi, M.
    • Lauteri, M.
    • Mantia, T. la
    • Velikova, V.
    • Loreto, F.
  • Source: Functional Plant Biology
  • Volume: 39
  • Issue: 3
  • Year: 2012
  • Summary: We investigated the consequences of recurrent winter flooding with saline water on a lemon ( Citrus * limon (L.) Burm.f.) orchard, focussing on photosynthesis limitations and emission of secondary metabolites (isoprenoids) from leaves and fruits. Measurements were carried out immediately after flooding (December), at the end of winter (April) and after a dry summer in which plants were irrigated with optimal quality water (September). Photosynthesis was negatively affected by flooding. The effect was still visible at the end of winter, whereas the photosynthetic rate was fully recovered after summer, indicating an unexpected resilience capacity of flooded plants. Photosynthesis inhibition by flooding was not due to diffusive limitations to CO 2 entry into the leaf, as indicated by measurements of stomatal conductance and intercellular CO 2 concentration. Biochemical and photochemical limitations seemed to play a more important role in limiting the photosynthesis of flooded plants. In young leaves, characterised by high rates of mitochondrial respiration, respiratory rates were enhanced by flooding. Flooding transiently caused large and rapid emission of several volatile isoprenoids. Emission of limonene, the most abundant compound, was stimulated in the leaves, and in young and mature fruits. Flooding changed the blend of emitted isoprenoids, but only few changes were observed in the stored isoprenoids pool.