• Authors:
    • Wang, J.
    • Yu, M.
    • Li, X. M.
    • Yang,J. S.
    • Liu, M. X.
  • Source: Ying Yong Sheng Tai Xue Bao
  • Volume: 22
  • Issue: 12
  • Year: 2011
  • Summary: A 2-year (2009 and 2010) field experiment was carried out to investigate the effects of irrigation amount (300, 375, and 450 mm) and irrigation frequency (once every 3-, 7-, and 10 days) on the soil water distribution and cotton water use efficiency (WUE) under mulched drip irrigation in North Xinjiang. When the irrigation amount was 375 mm, irrigation once every 3 days induced a higher water content in surface soil (0-20 cm) in the whole growth season of cotton but made the deeper (below 40 cm) soil not moistened enough. Irrigation once every 10 days benefited the irrigation water penetrated downward or sideways and made the deeper soil have a higher water content; however, this drip irrigation did not replenish water in time, and made the surface soil water content lower. Overall, drip irrigation once every 7 days benefited the uniform distribution of irrigation water in soil profile. Under the same irrigation frequencies, the larger the irrigation amount, the higher the soil water content. The cotton water consumption in all treatments had the similar pattern, i. e., lower at seedling stage (averagely
  • Authors:
    • Zhang, F.
    • Ma, D.
    • Ma, L.
  • Source: Chinese Potato Journal
  • Volume: 25
  • Issue: 2
  • Year: 2011
  • Summary: Drip irrigation and traditional irrigation were investigated for their effects on the percentage of large tubers and tuber yield in a field trial with a potato cv. Kexin No.18 ( Solanum tubersoum) in Keshan, Heilongjiang, China in 2010, with no irrigation as the control. The drip irrigation increased the percentage of large tubers, and increased tuber yield by 46.7%, and also significantly enhanced economic benefits, compared to traditional irrigation methods.
  • Authors:
    • Schubert, A. M.
    • Hudnall, W. H.
    • Booker, J. D.
    • Bronson, K. F.
    • Malapati, A.
  • Source: Journal of Soil and Water Conservation
  • Volume: 66
  • Issue: 5
  • Year: 2011
  • Summary: Sulfate (SO 4) is one of the most important anions in soils and groundwater in semiarid regions, including west Texas. Crops' sulfur (S) requirement is about 10% to 20% of the nitrogen requirements. However, there is far less information on soil test SO 4-S (S in the SO 4 form [sulfate-S]) for the western United States, compared to the humid eastern United States. The deposition of S from the atmosphere has declined nationwide, as coal-fired power plants have been scrubbing their emissions of S. This, combined with greater cotton yields and the lack of S fertilization on the Texas Southern High Plains (SHP) point to the need for a soil profile SO 4-S assessment. The first objective of this study was to assess residual soil profile SO 4-S content in irrigated cotton ( Gossypium hirsutum) fields across a range of soil types and counties of the Texas SHP. The second objective was to compile regional SO 4-S concentration data from the Texas Water Development Board irrigation well water quality database and analyze Ogallala groundwater SO 4-S levels by county, soil map unit, and well depth. Soil profile (0 to 0.9 m [0 to 36 in]) SO 4-S content ranged from 120 to 475 kg ha -1 (107 to 424 lb ac -1) among seven center-pivot fields sampled. About half of this S was in the 0.6 to 0.9 m (24 to 36 in) soil layer, which typically was sandy clay loam or clay loam in texture. Well water SO 4-S concentration ranged from 9 to 220 mg L -1 (ppm) in clayey soils with deep groundwater to sandy soils with shallow groundwater, respectively. Groundwater SO 4-S concentration was greater than the USEPA drinking water standard of 83 mg L -1 in 32% of the wells, especially in the southeastern corner of the study area. There was no consistent relationship between soil map unit and SO 4-S content in the soil profile (0 to 0.9 m). A significant negative relationship between well depth and well water SO 4-S concentration was observed in all the eleven-county study area of the SHP of West Texas. In conclusion, soil profile SO 4 content to 0.9 m is high in SHP irrigated cotton fields and in most cases should be adequate for crop S nutritional requirements.
  • Authors:
    • Shukla, S.
    • Harris, W. G.
    • Obreza,T. A.
    • Sartain, J. B.
    • Schumann, A. W.
    • Mann, K. K.
  • Source: Journal of Plant Nutrition and Soil Science
  • Volume: 174
  • Issue: 6
  • Year: 2011
  • Summary: Variability in soil properties is a complication for fertilization, irrigation, and amendment application. However, only limited progress has been made in managing soil variability for uniform productivity and increased water-use efficiency. This study was designed to ameliorate the poor-productivity areas of the variable sandy soils in Florida citrus groves by using frequent small irrigations and applying organic and inorganic soil amendments. Two greenhouse experiments were set up with sorghum and radish as bioassay crops in a randomized complete block design (RCBD). The factors studied were two soil-productivity classes (very poor and very good), two water contents (50% and 100% of field capacity), two amendments (phosphatic clay and Fe humate), and two amendment rates (10 and 25 g kg -1 for sorghum and 50 and 100 g kg -1 for radish). Amendments applied at 50 and 100 g kg -1 increased the water-holding capacity (WHC) of poor soil by 2- to 6-fold, respectively. The lower rates (10 and 25 g kg -1) of amendments were not effective in enhancing sorghum growth. The higher rates (50 and 100 g kg -1) doubled the radish growth as compared to the control. The results indicate that rates greater than 50 g kg -1 of both amendments were effective in improving water retention and increasing productivity. Irrigation treatment of 100% of field capacity (FC) increased the sorghum and radish growth by about 2-fold as compared with the 50%-water content treatment. The results suggest that the root-zone water content should be maintained near FC by frequent small irrigations to enhance water availability in excessively drained sandy soils. In addition, application of soil amendments in the root zone can enhance the water retention of these soils. Furthermore, managing variable sandy soils with WHC-based irrigation can increase water uptake and crop production in the poor areas of the grove.
  • Authors:
    • Janaki, D.
    • Haroon, A. R. M.
    • Maragatham, S.
  • Source: Advances in Plant Sciences
  • Volume: 24
  • Issue: 2
  • Year: 2011
  • Summary: Irrigation water is one of the most critical resource for agricultural production. Under ICAR-All India Coordinated Research Project functioning at Anbil Dharmalingam Agricultural College and Research Institute, Tiruchirappalli, water samples were collected from Tiruchirappalli and other adjacent districts for ground water characterization. Of these water samples collected, high SAR saline waters are found in Udiyur block of Kankeyam area, Erode district. A laboratory study was conducted to study the effect of high SAR saline water on germination per cent and biomass yield in cotton plants. Different sources of water and amendments were used. Maximum biomass yield and high germination per cent were recorded when best available water was used as a source of irrigation followed by gypsum treated water. The germination per cent was 90.0 and 82.5 respectively. Among the amendments, soil application of vermin compost (5 t ha -1) and press mud (t ha -1) registered higher germination per cent.
  • Authors:
    • Chachar, Q. I.
    • Shahzadi, A. K.
    • Mari, J. M.
  • Source: Journal of Agricultural Technology
  • Volume: 7
  • Issue: 1
  • Year: 2011
  • Summary: The study on perception of the problems in farming community in District Hyderabad, Pakistan was conducted through a set of questioners during 2007. Three hundred respondents (growers) were personally interviewed, their responses were tabulated. Data were collected on the basic information about cotton growers such as their ages, education, tenancy statuses, sizes of farm, farming experiences, and living status was asked which would highly influence the use of communication media for the perception of the problems in farming community. The growers of the area stated that irregular supply of irrigation and lack of visit of extension personnel, nonavailability of inputs, and high cost of inputs were common problems of the area. It was also noted that these are the causes for low yield. It is recommended that government should ensure the better facilities for continue supply of irrigation water and pure inputs with minimum rates in the market.
  • Authors:
    • Angelocci, L. R.
    • Marin, F. R.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 6
  • Year: 2011
  • Summary: Crop evapotranspiration (ETc) was measured as evaporative heat flux from an irrigated acid lime orchard ( Citrus latifolia Tanaka) using the aerodynamic method. Crop transpiration (T) was determined by a stem heat balance method. The irrigation requirements were determined by comparing the orchard evapotranspiration (ETc) and T with the reference evapotranspiration (ETo) derived from the Penman-Monteith equation, and the irrigation requirements were expressed as ETc/ETo (Kc) and T/ETo (Kcb) ratios. The influence of inter-row vegetation on the ETc was analyzed because the measurements were taken during the summer and winter, which are periods with different regional soil water content. In this study, the average Kc values obtained were 0.65 and 0.24 for the summer and winter, respectively. The strong coupling of citrus trees to the atmosphere and the sensitivity of citrus plants to large vapor pressure deficits and air/leaf temperatures caused variations in the Kcb in relation to the ETo ranges. During the summer, the Kcb value ranged from 0.34 when the ETo exceeded 5 mm d -1 to 0.46 when the ETo was less than 3 mm d -1.
  • Authors:
    • Martin-Gorriz, B.
    • Ruiz-Salleres, I.
    • Gonzalez-Real, M. M.
    • Baille, A.
    • Nortes, P. A.
    • Egea, G.
    • Verhoef, A.
  • Source: Acta Horticulturae
  • Issue: 922
  • Year: 2011
  • Summary: The focus of the work reported here is the impact of severe heat stress conditions on orchards' carbon dioxide exchange rate (NEE, Net Ecosystem Exchange). NEE was monitored by means of the eddy-covariance technique over an irrigated orange-tree orchard during summer 2009 in Southern Spain. In that period, severe heat spells occurred (maximum air temperature and vapour pressure deficit up to 38degreesC and 5 kPa, respectively). Under these conditions, orange trees maintained their transpiration rates at levels similar to those observed for normal sunny days, while canopy stomatal conductance and NEE were strongly reduced, thereby leading to a marked decrease in water use efficiency. The experimental results are discussed in the context of (i) stomatal and non-stomatal limitations to CO 2 exchange and (ii) orchard respiration loss. As the frequency of extreme events is expected to increase in the Mediterranean Basin, our results suggest that water productivity of irrigated orchards may be significantly affected by climate change.
  • Authors:
    • Mennone, C.
  • Source: Informatore Agrario
  • Volume: 67
  • Issue: 27
  • Year: 2011
  • Summary: Techniques to increase fruits size of clementine are mentioned, which include fruit thinning and use of plant growth regulators. The developmental stages of clementine fruits are described. Factors affecting fruit size, including genetic factors, variety, fruit number, competition among developing organs (flowers and fruits), external factors (climatic, edaphic (soil) and cultural practices such as pruning, fertilization, irrigation) and application of growth regulators are discussed. Results are presented of trials conducted in Metaponto, Italy, to investigate the efficacy of some plant growth regulators (triclopyr+MCPA and gibberellic acid (ester)) in increasing size and improving colour and quality of clementine fruits.
  • Authors:
    • Monserrat Delgado, A.
  • Source: Agricola Vergel: Fruticultura, Horticultura, Floricultura, Citricultura, Vid, Arroz
  • Volume: 30
  • Issue: 351
  • Year: 2011
  • Summary: Studies were conducted to determine the most important aspects to consider for the use of herbicides in citrus groves and fruit trees with irrigation. The design of strategies that suit the age of planting and soil characteristics, among others, were based on some of the factors that influence the efficacy and selectivity of the applications and its long-term profitability. To avoid the selection of hard to control weeds on the farm, some treatments described were utilized against some of the most important weed species. Some authorized herbicides in citrus production, with some observations of special interest, was also presented.