• Authors:
    • Huffman, R. L.
    • Grabow, G. L.
    • Evans, R. O.
  • Source: Journal of Irrigation and Drainage Engineering
  • Volume: 137
  • Issue: 1
  • Year: 2011
  • Summary: A subsurface drip irrigation (SDI) system was installed in the Piedmont of North Carolina in a clay soil in the fall of 2001 to test the effect of dripline spacing on corn and soybean yield. The system was zoned into three sections; each section was cropped to either corn ( Zea mays L.), full-season soybean [ Glycine max (L.) Merr.], or winter wheat ( Triticum aestivum) double cropped to soybean representing any year of a typical crop rotation in the region. Each section had four plots; two SDI plots with dripline spacing at either 1.52 or 2.28 m, an overhead sprinkler irrigated plot, and an unirrigated plot. There was no difference in average corn grain yield for 2002-2005 between dripline spacings or between either dripline spacing and sprinkler. Irrigation water use efficiency (IWUE) was greater for sprinkler irrigated corn than for either SDI treatment and there was no difference in IWUE in soybean. Water typically moved laterally from the driplines 0.38 to 0.50 m. SDI yield and IWUE increased relative to sprinkler yields and water use efficiency in the second and third year of the study. This may suggest that initial fracturing of the heavy clay soil during SDI system installation and subsequent settling of the soil affected water distribution.
  • Authors:
    • Burr, C.
    • Thorburn, J.
    • Irmak, S.
    • Yang, H. S.
    • Grassini, P.
    • Cassman, K. G.
  • Source: Field Crops Research
  • Volume: 120
  • Issue: 1
  • Year: 2011
  • Summary: Appropriate benchmarks for water productivity (WP), defined here as the amount of grain yield produced per unit of water supply, are needed to help identify and diagnose inefficiencies in crop production and water management in irrigated systems. Such analysis is lacking for maize in the Western U.S. Corn Belt where irrigated production represents 58% of total maize output. The objective of this paper was to quantify WP and identify opportunities to increase it in irrigated maize systems of central Nebraska. In the present study, a benchmark for maize WP was (i) developed from relationships between simulated yield and seasonal water supply (stored soil water and sowing-to-maturity rainfall plus irrigation) documented in a previous study; (ii) validated against actual data from crops grown with good management over a wide range of environments and water supply regimes ( n=123); and (iii) used to evaluate WP of farmer's fields in central Nebraska using a 3-y database (2005-2007) that included field-specific values for yield and applied irrigation ( n=777). The database was also used to quantify applied irrigation, irrigation water-use efficiency (IWUE; amount of yield produced per unit of applied irrigation), and the impact of agronomic practices on both parameters. Opportunities to improve irrigation management were evaluated using a maize simulation model in combination with actual weather records and detailed data on soil properties and crop management collected from a subset of fields ( n=123). The linear function derived from the relationship between simulated grain yield and seasonal water supply, namely the mean WP function (slope=19.3 kg ha -1 mm -1; x-intercept=100 mm), proved to be a robust benchmark for maize WP when compared with actual yield and water supply data. Average farmer's WP in central Nebraska was ~73% of the WP derived from the slope of the mean WP function. A substantial number of fields (55% of total) had water supply in excess of that required to achieve yield potential (900 mm). Pivot irrigation (instead of surface irrigation) and conservation tillage in fields under soybean-maize rotation had the greatest IWUE and yield. Applied irrigation was 41 and 20% less under pivot and conservation tillage than under surface irrigation and conventional tillage, respectively. Simulation analysis showed that up to 32% of the annual water volume allocated to irrigated maize in the region could be saved with little yield penalty, by switching current surface systems to pivot, improving irrigation schedules to be more synchronous with crop water requirements and, as a fine-tune option, adopting limited irrigation.
  • Authors:
    • Nascimento, J. J. V. R. do
    • Oliveira, G. dos S.
    • Silva, G. F. da
    • Pereira, R. G.
    • Paiva, M. R. de F. C.
  • Source: Revista Verde de Agroecologia e Desenvolvimento Sustentavel
  • Volume: 6
  • Issue: 2
  • Year: 2011
  • Summary: The planting of castor bean ( Ricinus communis L.) by seedlings can be an alternative for a better use of the short rainy season in the Brazilian semiarid, but in this region, irrigation water, almost always has a salt concentration that affects the quality of seedlings the vast majority of oil. In this context, this work was to study the effects of saline water at levels of 0.5, 1.5, 2.5, 3.5, 4.5 and 5.5 dS m -1 and two volumes substrate: 1.0 and 2.5 L on the germination and early growth of two castor bean cultivars (BRS BRS Paraguacu and Northeast). The study was conducted in the open at the Experimental Station of Embrapa Cotton, in Barbalha, Ceara. Treatments were arranged in randomized blocks in five replicates, using the factorial 2*2*6. Regardless of cultivar, although the saline water inhibits germination and plant development, the effects were more pronounced in treatments with lower volume of substrate. Both cultivars have suffered more the action of salinity on growth during the initial seed germination.
  • Authors:
    • Butts, C. L.
    • Sorensen, R. B.
    • Nuti, R. C.
  • Source: The Journal of Cotton Science
  • Volume: 15
  • Issue: 3
  • Year: 2011
  • Summary: Long-term cotton ( Gossypium hirsutum L.) yield with various irrigation rates and crop rotations, irrigated with subsurface drip irrigation (SSDI) is not known for the US Southeast. A SSDI system was installed in Southwest GA (1998) and maintained for 10 years. The soil is a Tifton loamy sand (Fine-loamy, kaolinitic, thermic Plinthic Kandiudults) and treatments consisted of three crop rotations, two drip tube lateral spacings, and three irrigation levels. Crop rotations were alternate year cotton (cotton-peanut; Arachis hypogeae L), two years (cotton-maize ( Zea mays L.) -peanut), and three years between cotton (cotton-maize-maize-peanut). Drip tube laterals were installed underneath each crop row and alternate crop row furrows. Cotton was not grown in 1999 and 2006. Crops were irrigated daily at 100, 75 and 50% of estimated crop water use. No lint yield difference resulted from crop rotation. Lint yield differences were attributed to irrigation treatments in 4 of 8 years. Lint yields were greatest at the 75% irrigation level compared to 50%, and in 3 out of 4 years compared to the 100% irrigation treatment. Higher lint yield with irrigation also coincided with lower seasonal rainfall totals. Drip tube lateral spacing affected lint yield 4 out of 8 years. Across all years, yield data indicates that alternate row furrow lateral spacing is as effective as every-row lateral spacing. Some fiber qualities were affected by irrigation, lateral, and rotation treatments, but these effects were small and inconsistent. Subsurface drip irrigation in the Southeast is optimal at the 75% irrigation level with tubing in alternate row furrows.
  • Authors:
    • Carvalho, D. F. de
    • Botrel, T. A.
    • Souza, W. J.
    • Silva, L. D. B. da
  • Source: Revista Brasileira de Engenharia Agrícola e Ambiental
  • Volume: 15
  • Issue: 8
  • Year: 2011
  • Summary: The use of localized irrigation using microtube as emitter under turbulent flow regime can be a technically feasible alternative. The objective of this study was to evaluate the performance of a fertigation system in nursery of citrus plants (greenhouse) projected by universal mathematical model, using the microtubes as emitters, under turbulent flow rate and to compare the development of the fertigated plants by microtubes to the system that use the traditional method with hoses. In the size of the length of the emitters was considered the K coefficient of localized energy dissipation using a microtube with internal diameter of 0,761 mm. The fertigation system presented great performance with clogging degree, Christiansen uniformity and emission uniformity values equal to 0,50; 99,95 and 98,21%, respectively, after 160 days of study. Plants that were grown using fertigation with both microtubes and hoses showed no difference as regards to stem diameter and height. Thus, the use of the microtube under turbulent flow rate presented technical feasible for fertigation system.
  • Authors:
    • Ramalingam, A.
    • Srinivasan, G.
  • Source: Journal of Cotton Research and Development
  • Volume: 25
  • Issue: 2
  • Year: 2011
  • Summary: Field experiment was carried out in summer 2007 and 2008 to evaluate the response of summer irrigated cotton to foliar nutrition of potassium as an alternative to soil application. The results revealed that highest seed cotton yield of 1854 kg/ha was recorded only with the soil application of recommended level of potassium in 4 equal splits at sowing, seedling, flowering and boll development stage. This was comparable with 4 sprays of KNO 3 (2%) at 60, 75, 90 and 105 days after sowing (1665 kg/ha). The economics of cultivation also revealed that soil application of recommended level of potassium in 4 spits was advantageous with the highest BC ratio of 2.11 indicating the superiority of soil application of potassium over foliar application.
  • Authors:
    • Germana, C.
    • Intrigliolo, F.
    • Giuffrida, A.
    • Stagno, F.
    • Continella, A.
  • Source: Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: During three consecutive years, in a citrus orchard planted with Tarocco 'Meli' and 'Scire' on sour orange ( C. aurantium L.) were verified the differences of the plant water status and the possibility to build an empirical model to estimate the psi pd utilizing stem water potential (psi md) and vapor pressure deficit (VPD md) measured at midday. The first results showed statistical differences during the irrigation season in the two clones water potential. These difference permitted to separate the data of Tarocco 'Meli' and 'Scire'. As a result, two empirical models were built. The 2nd degree equation (Psi pd=a+b 1Psi md+b 2VPD md) was obtained by considering the Psipd as dependent variable, the Psi md and the VPD md as explanatory variables. ANOVA applied to the multiple regression resulted highly significant with P-value
  • Authors:
    • Yudong, S.
    • Tumaerbai, H.
    • Shalamu, A
    • Litan, S.
  • Source: ACTA PEDOLOGICA SINICA
  • Volume: 48
  • Issue: 4
  • Year: 2011
  • Summary: Soil salinization has become more and more severe in arid regions. Make an appropriate irrigation regimes to leaching soil salinity is a key scientific issue under drip irrigation in the silt loam soil in arid region. A 3-year field experiment was carried out to investigate the effects of different drip irrigation regimes on soil salinity distribution and cotton yield at Akesu agricultural ecosystem national scientific research station, Chinese Academy of Sciences. Throughout cotton growing season, the peak cure of soil salt under mulch moved downward with the increases of DIA (drip irrigation amount). The quantity of drip irrigation increased from 3 000 m 3 hm -2 to 4 800 m 3 hm -2, peak value of soil salt moved downward from 35 cm to 65 cm. The results showed that the peak cure of soil salt under mulch decreased in the order 1.6 DIA > 1.4 DIA > 1.2 DIA > DIA after irrigation. At the same time, the peak cure of soil salt under mulch also moved downward with the increases of drip irrigation discharge rates for all treatments except 3.2 L h -1 treatments because of the capability of infiltration of porosity of soil less than the drip irrigation discharge rate. The peak cure of soil salt under mulch decreased in the order 2.6 L h -1 >2.2 L h -1 > 1.8 L h -1 > 3.2 L h -1 after irrigation. The soil salinity moved gradually from deep soil to surface soil and moved slowly from under mulch to inter-mulch simultaneously with elapse time. With the increasing of quantity of drip irrigation or drip irrigation discharge rates, seed yield presenting increased except 1.6 DIA and 3.2 L h -1 treatment. Both water deficit and heavy irrigation will decrease the cotton yield, as well as the high and law drip irrigation discharge rate. Therefore, quantity of drip irrigation of 1.4 DIA and appropriate drip irrigation discharge rate of 2. 6 L h -1 was the best drip irrigation regimes for the higher cotton yield in the silt loam soil in arid region.
  • Authors:
    • Ichinokiyama, H.
    • Suzaki, N.
    • Okuda, H.
  • Source: Agricultural Information Research
  • Volume: 20
  • Issue: 3
  • Year: 2011
  • Summary: In commercial orchards of satsuma mandarin in Japan, mulching cultivation has been developed to produce high quality fruit. It is, however, difficult to manage irrigation to produce consistent characteristics such as high fruit quality, fruit productivity, and tree vigor. The principal reason for this is that no simple, easy, and reliable indicator has been developed to evaluate tree water deficits. In this study, we demonstrated that the morning maximum leaf water potential could be estimated using the fruit hardness in the evening of the previous day. To assist farmers in estimating fruit hardness, we developed a set of three silicone rubber balls with different degrees of hardness as a reference tool, and verified their effectiveness. The experiment was performed in 2008 and 2009, and revealed that irrigation management during July and August using the silicone rubber reference balls gave good results, with high fruit quality and high fruit productivity. Fruit hardness estimated using the silicone rubber balls therefore appears to be a good indicator of irrigation management during July and August for mulched citrus orchards.
  • Authors:
    • Farajzadeh, N.
    • Yarnia, M.
    • Tabrizi, E. F. M.
    • Ahmadzadeh, V.
  • Source: Annals of Biological Research
  • Volume: 2
  • Issue: 5
  • Year: 2011
  • Summary: Potato tuber products that has an important role in feeding the world with annual production of 31 million tons of food products is important and different types of soil and climatic conditions is growing culture. Potato after wheat, rice and corn for the fourth position and the number of producing countries is in the second after the corn. A factorial experiment based on randomized complete block design with three replications was conducted during growing season of 2009 at Islamic Azad University, Tabriz branch, Agricultural Research Station. Treatments including: irrigation of 70 (control), 110, 150 mm evaporation from basin class A and different varieties of potato, including (Agria, Satyna, Savalan, Kaizr and Markis) respectively. The results showed that water stress decreased yield and lowest yield was in cultivar Markis with 150 mm of irrigation water evaporation basin level and most resistant cultivars in the rate of tuber production with 10.68 numbers has been obtained Satyna. Equivalent of 96.12 percent increase than sensitive cultivars. Therefore aim of this study reaction of different cultivars of potato on different traits.