• Authors:
    • Gomez-Macpherson, H.
    • Mateos, L.
    • Boulal, H.
  • Source: Irrigation Science
  • Volume: 29
  • Issue: 5
  • Year: 2011
  • Summary: Zero tillage and controlled traffic have been proposed as means for more productive and sustainable irrigated farming. Both practices affect soil infiltration characteristics and, therefore, should have effects on sprinkler irrigation performance. This study compared water infiltration and runoff in three sprinkler irrigation tests performed on an alluvial loam soil at different times during a maize (Zea mays L.)-cotton (Gossypium hirstium L.) rotation under two soil managements: permanent beds with crop residue retention (PB: planting beds maintained unaltered from year to year) and conventional beds with residues incorporated with tillage (CB: disc and chisel ploughing followed by rotavator pass and bed forming every year). Traffic was controlled and two types of furrows were distinguished in both tillage systems: with (+T) and without (-T) wheel traffic. The irrigation tests were performed on maize at full cover, on bare soil just before cotton sowing and on cotton with 50% ground cover. Infiltration and runoff were affected notably by both traffic and soil management. The soil under PB infiltrated more water than under CB, and -T furrows more than +T furrows. Considering the combined treatments, -T furrows in the CB system infiltrated more water than +T furrows in the PB system. A sprinkler irrigation model for simulating water application and soil infiltration and runoff was formulated. The model was used to analyse irrigation performance under infiltration characteristic of the CB and PB systems in trafficked and non-trafficked furrows. Five irrigation performance indicators were used to assess the various combinations of tillage and traffic: Wilkox-Swailes coefficient of uniformity; application efficiency; deep percolation ratio; tail water ratio; and adequacy. The model was used to develop operation diagrams and provided guidelines for making irrigation decisions in the new controlled traffic/permanent bed system and in a standard conventional system.
  • Authors:
    • Liscano,J. F.
    • Boquet, D. J.
    • Breitenbeck, G. A.
    • Mascagni, H. J.,Jr.
    • Clawson, E. L.
    • McCarter, K. S.
  • Source: Journal of Plant Nutrition
  • Volume: 34
  • Issue: 6
  • Year: 2011
  • Summary: Soil nitrogen (N)-supplying capacity bioassays could present alternatives to traditional soil tests. Objectives were to identify winter crops and associated characteristics with bioassay potential. Saint Joseph and Bossier City, LA experiments used randomized complete block designs with factorial N fertilizer and winter crop treatment arrangements. Nitrogen rates were applied to corn (Zea mays L.) in 2004. Unfertilized winter wheat (Triticum aestivum L.), cereal rye (Secale cereale L.), native winter vegetation, and weed-free winter fallow treatments followed corn. At Saint Joseph, cotton (Gossypium hirsutum L.) followed winter crop treatments. Greater corn N rate consistently increased winter crop biomass and N accumulation, suggesting potential as bioassays, and increased Saint Joseph seedcotton yield. Winter crop-seedcotton yield N-response relationships were non-significant by familywise error rate criteria. However, some winter crop characteristics, such as rye N accumulation, for which a relationship to seedcotton yield closely approached significance, may merit further research as soil N-supplying capacity bioassays.
  • Authors:
    • Klein, D.
    • Dech, S.
    • Colditz, R. R.
    • Conrad, C.
    • Vlek, P. L. G.
  • Source: International Journal of Remote Sensing
  • Volume: 32
  • Issue: 23
  • Year: 2011
  • Summary: Crop cover and crop rotation mapping is an important and still evolving field in remote sensing science for which robust and highly automated processing chains are required. This study presents an improved mapping procedure for crop rotations of irrigated areas in Central Asia by using classification and regression trees (CARTs) applied to transformations of 250 m Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) time series. The time series were divided into several temporal segments, from which metrics were derived as input features for classification. This temporal aggregation was applied to suppress within-class temporal variability. Various lengths of temporal segments were tested for their potential to increase classification accuracy. In addition, tests of enhancing the classification accuracy were done by combining different classification results using the majority rule for voting. These different processing strategies were applied to four annual time series (2004-2007) of the Khorezm region, where 270 000 ha of irrigated land is dominated by rotations of cotton, wheat and rice. Improved classification results were obtained for CARTs applied to metrics derived from a mixture of different segment lengths. The sole use of either long or short temporal segments was inferior. CART prioritized segments representing active phases of the phenological development. The best result, the optimized segment-based approach, achieved an overall accuracy between 83 and 85% for classifications between 2004 and 2007; in particular, the small range demonstrated the robustness regarding inter-annual variations. These accuracies exceeded those of the original time series without temporal segmentation by 6-7%. With some adjustments to other crops and field heterogeneity influencing the usefulness of a respective sensor, the approach can be applied to other irrigation systems in Central Asia.
  • Authors:
    • Paustian, K.
    • Ogle, S.
    • Lee, J.
    • De Gryze, S.
    • Six, J.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 144
  • Issue: 1
  • Year: 2011
  • Summary: We predicted changes in yields and direct net soil greenhouse gas (GHG) fluxes from converting conventional to alternative management practices across one of the world's most productive agricultural regions, the Central Valley of California, using the DAYCENT model. Alternative practices included conservation tillage, winter cover cropping, manure application, a 25% reduction in N fertilizer input and combinations of these. Alternative practices were evaluated for all unique combinations of crop rotation, climate, and soil types for the period 1997-2006. The crops included were alfalfa, corn, cotton, melon, safflower, sunflower, tomato, and wheat. Our predictions indicate that, adopting alternative management practices would decrease yields up to 5%. Changes in modeled SOC and net soil GHG fluxes corresponded to values reported in the literature. Average potential reductions of net soil GHG fluxes with alternative practices ranged from -0.7 to -3.3 Mg CO(2)-eq ha(-1) yr(-1) in the Sacramento Valley and -0.5 to -2.5 Mg CO(2)-eq ha(-1) yr(-1) for the San Joaquin Valley. While adopting a single alternative practice led to modest net soil GHG flux reductions (on average -1 Mg CO(2)-eq ha(-1) yr(-1)), combining two or more of these practices led to greater decreases in net soil GHG fluxes of up to -3 Mg CO(2)-eq ha(-1) yr(-1). At the regional scale, the combination of winter cover cropping with manure application was particularly efficient in reducing GHG emissions. However, GHG mitigation potentials were mostly non-permanent because 60-80% of the decreases in net soil GHG fluxes were attributed to increases in SOC, except for the reduced fertilizer input practice, where reductions were mainly attributed to decreased N(2)O emissions. In conclusion, there are long-term GHG mitigation potentials within agriculture, but spatial and temporal aggregation will be necessary to reduce uncertainties around GHG emission reductions and the delivery risk of the associated C credits. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Gupta, U. S.
  • Year: 2011
  • Summary: This volume looks at the use of crops for a myriad of purposes, including the prevention and/or mitigation of various diseases, vaccine and antigen production, biofuel production, and the the suppression of weeds. It explores new emnphasis on medicinal properties of crops and examines the use of genetic engineering in crop production. The crops discussed include: rice, wheat, barley, oat, rye, maize, sorghum, potato, sweet potato, cassava, Phaseolus beans, Vigna sp., broad bean, chickpea, tomato, broccoli, cauliflower, cabbage, bitter gourd, pumpkin, spinach, onion, soyabean, groundnut, oilseed Brassica, sunflower, sugarcane, cotton, and tobacco.
  • 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:
    • 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:
    • 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:
    • Koc, D. L.
    • Tekin, S.
    • Kapur, B.
    • Kanber, R.
    • Unlu, M.
  • Source: African Journal of Biotechnology
  • Volume: 10
  • Issue: 12
  • Year: 2011
  • Summary: This study was carried out to determine the crop water stress index (CWSI) for drip irrigated cotton grown on a heavy clay texture soil ( Palexerollic Chromoxerert) under semi-arid climatic condition of East Mediterranean region for three years (2005 to 2007) in Adana, Turkey. Four irrigation treatments designated as full (I 100) with no water stress and slight (DI 70), moderate (DI 50) and strong water stress (continuous stress, dry land) (DI 00) were tested. The treatments of DI 70 and DI 50 received water amount of 70 and 50% of the control treatment and the DI 00 was not irrigated except for germination water given at the beginning of the growing season. Irrigation was initiated when leaf water potential (LWP) reached to -15 bar for full (I 100), -17 bar for DI 70 and -20 bar for DI 50 irrigation treatments. After first irrigation, all the treatments were irrigated at one week interval. The deficit irrigation affected, the irrigation water use, seed cotton yield, dry matter and some yield components such as plant height and number of boll per plant of cotton. Average values of water use, seed cotton yield, dry matter and water use efficiency of full irrigated cotton were 578 mm, 3.28 tha -1, 13.44 tha -1 and 0.59 kgm -3, respectively. CWSI values were calculated from the measurements of canopy temperatures by infrared thermometer (IRT), ambient air temperatures and vapor pressure deficit values for all the irrigated treatments. A non-water stressed baseline (lower baseline) equation for cotton was developed using canopy temperature measured from full irrigated plots as, T c - T a =-1.7543 VPD+1.56; R 2=0.5327 and the non-transpiring baseline (upper baseline) equation was built using canopy temperature data taken from continuous stress plots as, T c - T a =-0.0217 VPD+3.2191. The trends in CWSI values were consistent with the varying soil water content due to the deficit irrigation programs. The relationships between mean CWSI and plant parameters considered in this study were linear except for irrigation water amount. Both dry matter and seed cotton yield decreased with increased soil water deficit. Seed cotton yield (SY) and seasonal mean CWSI values relationship were obtained as, SY=-2.3552 CWSI+3.5657; R 2=0.499. This relationship can be used to predict the seed cotton yield. The results suggest that the cotton crop for this particular climate and soil conditions, should be irrigated when CWSI approaches 0.36. The CWSI approach, according to results of this study, can be accepted as a useful tool to schedule irrigations for cotton.
  • Authors:
    • Kapur, B.
    • Tekin, S.
    • Koc, D. L.
    • Kanber, R.
    • Unlu, M.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 4
  • Year: 2011
  • Summary: A field study on cotton ( Gossypium hirsutum L., cv.) was carried out from 2005 to 2008 in the Cukurova Region, Eastern Mediterranean, Turkey. Treatments were designated as I100 full irrigation; DI 70, DI 50 and DI 00 which received 70, 50, and 0% of the irrigation water amount applied in the I100 treatment. The irrigation water amount to be applied to the plots was calculated using cumulative pan evaporation that occurred during the irrigation intervals. The effect of water deficit or water stress on crop yield and some plant growth parameters such as yield response, water use efficiencies, dry matter yield (DM), leaf area index (LAI) as well as on lint quality components was evaluated. The average seasonal evapotranspiration ranged from 28715 (DI 00) to 58480 mm ( I100). Deficit irrigation significantly affected crop yield and all yield components considered in this study. The average seed cotton yield varied from 1369197 (DI 00) to 3397508 kg ha -1 ( I100). The average water use efficiency (WUE ET) ranged from 6.01.6 ( I100) to 4.80.9 kg ha -1 mm -1 (DI 00), while average irrigation water use efficiency (WUE I) was between 9.43.0 ( I100) and 14.44.8 kg ha -1 mm -1 (DI 50). Deficit irrigation increased the harvest index (HI) values from 0.260.054 ( I100) to 0.320.052 kg kg -1 (DI 50). Yield response factor (Ky) was determined to be 0.98 based on four-year average. Leaf area index (LAI) and dry matter yields (DM) increased with increasing water use. This study demonstrated that the full irrigated treatment ( I100) should be used for semiarid conditions with no water shortage. However, DI 70 treatment needs to be considered as a viable alternative for the development of reduced irrigation strategies in semiarid regions where irrigation water supplies are limited.