Cotton Water Use Research Articles

Residue Management Effects on Water Use and Yield of Deficit Irrigated Cotton

The declining saturated thickness of the Ogallala Aquifer beneath the southern High Plains decreases irrigation well capacity and necessitates conservation of precipitation for crop use. A 3‐yr dryland crop rotation of wheat (Triticum aestivum L.) followed by cotton (Gossypium hirsutum L.) with intervening 10‐mo fallow periods was adapted for use with deficit irrigation of 2.5 and 5.0 mm d−−1 capacities on a Pantex silty clay loam (fine, mixed, superactive, thermic Torrertic Paleustoll) managed with disk (DT), stubble‐mulch (SM), or no (NT)‐tillage at Bushland, TX (35.183° N, 102.1° W). Study objectives were to quantify tillage effects on soil water storage during wheat fallow and any continued effects on water use and yield by deficit irrigated cotton. Compared with DT, wheat residue cover increased mean fallow precipitation storage by ∼15 mm for SM and 50 mm with NT based on significant differences in 3 of 4 yr. The significant differences in cotton water use between irrigation capacities totaled from 70% to ∼100% of the estimated evapotranspiration, ET. Measured growing season water use decreased with decreasing residue cover in the order NT > SM > DT. Cotton lint yield did not vary between irrigation capacities, but increased with NT by ∼50% or 450 kg ha−1 over DT. Yields for DT cotton irrigated at 5 mm d−1 were typically less than for NT and SM cotton irrigated at 2.5 mm d−1. Lint yield for NT management was significantly greater than DT, which we attributed to reduced evaporation and greater transpiration with NT residue.

Water-use efficiency and productivity trends in Australian irrigated cotton: a review

The aim of this review is to report changes in irrigated cotton water use from research projects and on-farm practice-change programs in Australia, in relation to both plant-based and irrigation engineering disciplines. At least 80% of the Australian cotton-growing area is irrigated using gravity surface-irrigation systems. This review found that, over 23 years, cotton crops utilise 6–7 ML/ha of irrigation water, depending on the amount of seasonal rain received. The seasonal evapotranspiration of surface-irrigated crops averaged 729 mm over this period. Over the past decade, water-use productivity by Australian cotton growers has improved by 40%. This has been achieved by both yield increases and more efficient water-management systems. The whole-farm irrigation efficiency index improved from 57% to 70%, and the crop water use index is >3 kg/mm.ha, high by international standards. Yield increases over the last decade can be attributed to plant-breeding advances, the adoption of genetically modified varieties, and improved crop management. Also, there has been increased use of irrigation scheduling tools and furrow-irrigation system optimisation evaluations. This has reduced in-field deep-drainage losses. The largest loss component of the farm water balance on cotton farms is evaporation from on-farm water storages. Some farmers are changing to alternative systems such as centre pivots and lateral-move machines, and increasing numbers of these alternatives are expected. These systems can achieve considerable labour and water savings, but have significantly higher energy costs associated with water pumping and machine operation. The optimisation of interactions between water, soils, labour, carbon emissions and energy efficiency requires more research and on-farm evaluations. Standardisation of water-use efficiency measures and improved water measurement techniques for surface irrigation are important research outcomes to enable valid irrigation benchmarks to be established and compared. Water-use performance is highly variable between cotton farmers and farming fields and across regions. Therefore, site-specific measurement is important. The range in the presented datasets indicates potential for further improvement in water-use efficiency and productivity on Australian cotton farms.

Estimating Crop Water Use of Cotton in the Texas High Plains

The growth and yield of cotton (Gossypium hirsutum L.) in the semiarid Texas High Plains is driven by the amount of water available to the crop through rainfall and irrigation. Various methods have been developed for quantifying the crop water use (CWU) of agricultural crops. In this study, we described a method for estimating CWU that uses a modified version of the Penman–Monteith Equation. In this method, CWU is equal to the transpiration of a well‐watered crop with complete ground cover (determined from ambient environmental conditions) multiplied by the amount of plant canopy present (quantified by crop ground cover) and a parameter (Fs) related to the effects of stomatal closure. For irrigated and dryland cotton that are acclimated to their respective environments, Fs ≈ 1. This suggests that control of canopy leaf area is a primary mechanism for acclimating to the surrounding environment. When Fs < 1, the plant is not acclimated with its environment and must rely on stomatal closure to conserve available water in the root zone. The method was developed using surface energy balance data and remotely sensed crop ground cover for three fields near Lubbock, TX. This method could be used in irrigation scheduling where irrigation is used to replace the daily CWU of a crop. This approach might be superior to the standard crop coefficient approach because it could use remotely sensed crop ground cover as a “spectral crop coefficient” that would make the resulting estimates of CWU specific to individual fields.

Cotton Water Use and Lint Yield in Four Great Plains Soils

The development of earlier maturing, cool temperature tolerant varieties of cotton (Gossypium hirsutum L.) has allowed cotton production to expand into regions with shorter, cooler growing seasons. The objective of this research was to evaluate the interactive effect of soil type, irrigation, and meteorological conditions on the water use and lint yield of cotton grown in four U.S. Great Plains soils. Cotton was grown in 2005 through 2007 in 48 weighing lysimeters which contained clay loam, silt loam, sandy loam, or fine sand at Bushland, TX, with irrigation beginning after emergence. The seasonal heat units (HU) from planting to harvest were 1010°C in 2005, 1075°C in 2006, and 985°C in 2007. From seedling to beginning boll development, reference evapotranspiration averaged 7.6 mm in 2005, 8.5 mm in 2006, and 6.7 mm in 2007. Lint yield was significantly related to open boll number at harvest in all soils and years. Averaged cotton lint yields for the 2005 and 2007 full and deficit irrigation treatments were significantly larger in the fine sand (160 g m−2) than in the other soils (126 g m−2). In 2006, cotton lint yield in the fine sand was significantly smaller (101 g m−2) than the average of the other soils (147 g m−2). Cotton lint yield increased in the silt loam soil and decreased in the fine sand as seasonal HU increased. Early season meteorological conditions which influenced square shedding and boll development may have affected lint yields interactively with soil texture and irrigation.

A review of the changes in soil quality and profitability accomplished by sowing rotation crops after cotton in Australian Vertosols from 1970 to 2006

In agricultural systems, soil quality is thought of in terms of productive land that can maintain or increase farm profitability, as well as conserving soil resources so that future farming generations can make a living. Management practices which can modify soil quality include tillage systems and crop rotations. A major proportion of Australian cotton (Gossypium hirsutum L.) is grown on Vertosols (~75%), of which almost 80% is irrigated. These soils have high clay contents (40–80 g/100 g) and strong shrink–swell capacities, but are frequently sodic at depth and prone to deterioration in soil physical quality if incorrectly managed. Due to extensive yield losses caused by widespread deterioration of soil structure and declining fertility associated with tillage, trafficking, and picking under wet conditions during the middle and late 1970s, a major research program was initiated with the objective of developing soil management systems which could improve cotton yields while concurrently ameliorating and maintaining soil structure and fertility. An outcome of this research was the identification of cotton–winter crop sequences sown in a 1 : 1 rotation as being able to sustain lint yields while at the same time maintaining soil physical quality and minimising fertility decline. Consequently, today, a large proportion (~75%) of Australian cotton is grown in rotation with winter cereals such as wheat (Triticum aestivum L.), or legumes such as faba bean (Vicia faba L.). A second phase of research on cotton rotations in Vertosols was initiated during the early 1990s with the main objective of identifying sustainable cotton–rotation crop sequences; viz. crop sequences which maintained and improved soil quality, minimised disease incidence, facilitated soil organic carbon sequestration, and maximised economic returns and cotton water use efficiency in the major commercial cotton-growing regions of Australia. The objective of this review was to summarise the key findings of both these phases of Australian research with respect to soil quality and profitability, and identify future areas of for research. Wheat rotation crops under irrigated and dryland conditions and in a range of climates where cotton is grown can improve soil quality indicators such as subsoil structure, salinity, and sodicity under irrigated and dryland conditions, while leguminous crops can increase available nitrogen by fixing atmospheric nitrogen, and by reducing N volatilisation and leaching losses. Soil organic carbon in most locations has decreased with time, although the rate of decrease may be reduced by sowing crop sequences that return about 2 kg/m2.crop cycle of residues to the soil, minimising tillage and optimising N inputs. Although the beneficial effects of soil biodiversity on quality of soil are claimed to be many, except for a few studies on soil macrofauna such as ants, conclusive field-based evidence to demonstrate this has not been forthcoming with respect to cotton rotations. In general, lowest average lint yields per hectare were with cotton monoculture. The cotton–wheat systems generally returned higher average gross margins/ML irrigation water than cotton monoculture and other rotation crops. This indicates that where irrigation water, rather than land, is the limiting resource, cotton–wheat systems would be more profitable. Recently, the addition of vetch (Vicia villosa Roth.) to the cotton–wheat system has further improved average cotton yields and profitability. Profitability of cotton–wheat sequences varies with the relative price of cotton to wheat. In comparison with cotton monoculture, cotton–rotation crop sequences may be more resilient to price increases in fuel and fertiliser due to lower overall input costs. The profitability of cotton–rotation crop sequences such as cotton–wheat, where cotton is not sown in the same field every year, is more resilient to fluctuations in the price of cotton lint, fuel and nitrogen fertiliser. This review identified several issues with respect to cotton–rotation crop sequences where knowledge is lacking or very limited. These are: research into ‘new’ crop rotations; comparative soil quality effects of managing rotation crop stubble; machinery attachments for managing rotation crop stubble in situ in permanent bed systems; the minimum amount of crop stubble which needs to be returned per cropping cycle to increase SOC levels from present values; the relative efficacy of C3 and C4 rotation crops in relation to carbon sequestration; the interactions between soil biodiversity and soil physical and chemical quality indicators, and cotton yields; and the effects of sowing rotation crops after cotton on farm and cotton industry economic indicators such as the economic incentives for adopting new cotton rotations, farm level impacts of research and extension investments, and industry- and community/catchment-wide economic modelling of the impact of cotton research and extension activities.

Water use efficiency of irrigated cotton in Uzbekistan under drip and furrow irrigation

The main goal of this research was to measure cotton water use, and to determine irrigation water scheduling parameters associated with optimal seed-lint yield and irrigation water use efficiency, which are poorly understood in the Central Asian Republic of Uzbekistan. A cotton ( Gossypium hirsutum L.) field experiment with drip irrigation in comparison to furrow (conventional) irrigation was conducted on a deep silt loam soil (Calcic Xerosol) at the Central Experiment Station of the Uzbekistan National Cotton Growing Research Institute at Tashkent in 2003, 2004 and 2005. To investigate irrigation scheduling, the field capacity ( F C) index was adopted, which was 0.30 m 3 m −3 in this soil. Irrigations were scheduled when soil water in the root zone was depleted to specific fractions of F C, e.g., 70% of F C, for each of three main plant growth periods (germination–squaring; squaring–flowering; beginning of maturation–maturation). Crop water use, which we here define as the sum of transpiration and evaporation, was established using the soil water balance approach on a weekly basis. Soil profile water content was determined using a neutron moisture meter (NMM), which was calibrated in polyvinyl chloride (PVC) access tubes for each differing soil layer. Under drip irrigation and the optimal mode (70–70–60% of F C) of irrigation scheduling, 18–42% of the irrigation water was saved in comparison with furrow irrigated cotton grown under the same condition; and irrigation water use efficiency increased by 35–103% compared with that of furrow irrigation. Seed-lint cotton yield was increased 10–19% relative to that for furrow irrigated cotton. The irrigation scheduling rule developed here should be considered an improved practice for drip irrigated cotton that is applicable to irrigated Calcic Xerosols of Uzbekistan.

Calibration of the Root Zone Water Quality Model for Simulating Tile Drainage and Leached Nitrate in the Georgia Piedmont

Calibration procedures and data used to parameterize a model, including model components that may or may not have been addressed, are generally not well documented in modeling studies. A comprehensive description of the process and parameters used for calibrating the Root Zone Water Quality Model, v. 1.3.2004.213, is presented in this article. The model was calibrated to simulate tile drainage and leached nitrate under conventional tillage management practices for maize (Zea mays L.) production followed by a rye (Secale cereale L.) cover crop in Cecil soils (kaolinitic, thermic, Typic Kanhapludults), and for cotton (Gossypium hirsutum L.) development in the Georgia Piedmont. Tile drainage and nitrate leaching were simulated within 15% of the observed values in the calibrated maize scenarios with and without the soil macroporosity option. Simulated and observed tile drainage and leached nitrate were not significantly different, and the simulated values were not significantly different with and without the macroporosity option. Simulated cotton biomass and leaf area index were well correlated with observed biomass and leaf area index until the last 21 d of the reproductive stage. Simulated and observed cotton water use were different by <1 mm d−1 based on Δ soil water in a 60‐cm profile during the critical peak bloom period. A detailed analysis of the calibration procedure and parameters used in this study will aid subsequent users of the model as well as aid in a subsequent evaluation of the model's performance for simulations of tile drainage and nitrate leaching in Georgia Piedmont cotton production systems.

Evapotranspiration of Full-, Deficit-Irrigated, and Dryland Cotton on the Northern Texas High Plains

Cotton (Gossypium hirsutum L.) is beginning to be produced on the Northern Texas High Plains as a lower water-requiring crop while producing an acceptable profit. Cotton is a warm season, perennial species produced like an annual yet it requires a delicate balance of water and water deficit controls to most effectively produce high yields in this thermally limited environment. This study measured the water use of cotton in fully irrigated, deficiently irrigated, and dryland regimes in a Northern Texas High Plains environment using precision weighing lysimeters in 2000 and 2001. A lateral-move sprinkler system was used to irrigate the fields. The water use data were used to develop crop coefficient data and compared with the FAO-56 method for estimating crop water use. Cotton yield, water use, and water use efficiency was found to be as good in this region as other more noted cotton regions. FAO-56 evapotranspiration prediction procedures performed better for the more fully irrigated treatments in this environment.

99/02098 Potential for reducing CO 2 from fossil fuel through biomass : Dote, Y. Jidosha Gliutsu, 1998, 52, (7), 12–16. (In Japanese)

Assessing the impacts of biofuel-induced land use change on hydrology, water quality and crop yield under the current and future climate scenarios enables selection of appropriate land uses and associated best management practices under the changing climate. In this study, the impacts of land use change from cotton (Gossypium hirsutum L.) to perennial grasses in the Double Mountain Fork Brazos watershed in the Texas High Plains were assessed using the Soil and Water Assessment Tool (SWAT). While switchgrass (Panicum virgatum L.) was assumed to replace cotton in irrigated areas, dryland cotton was replaced by Miscanthus × giganteus under the hypothetical land use change scenarios. Climate change impacts were assessed based on the Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections of 19 General Circulation Models (GCMs) under two Representative Concentration Pathway (RCP) emission scenarios of RCP4.5 and RCP8.5 during two 30-year periods of middle (2040–2069) and end (2070–2099) of the 21st century. Median irrigation water use of cotton was simulated to decrease by 41%–61% in the future when compared to historic (1994–2009) period based on projections by 19 GCMs. Under the future climate change scenarios, when compared to cotton, median annual irrigation water use by switchgrass reduced by 62%–89%. Simulated future median total nitrogen load decreased by 30%–40% under perennial grasses when compared to future cotton land use. The median irrigated switchgrass yield decreased by 16%–28%, but the median dryland Miscanthus yield increased by 32%–38% under the future climate change scenarios.

Effects of Elevated CO2 on Cotton and Wheat As Determined from FACE Experiments

In order to determine the effects of the increasing atmospheric CO2 concentration on future crop productivity and water requirements, free-air CO2 enrichment (PACE) experiments at 550μmol/mol CO2 have been conducted in an open field at Maricopa, Arizona, U.S.A., on cotton (Gossypium hirsutum L., cv. Deltapine 77) and wheat (Triticum aestivum L. cv. Yecora Rojo) crops at ample (Wet) and limiting (Dry) levels of water supply. With ample water, canopy net photosynthesis rates of cotton and wheat crops increased about 30-40%, with little evidence of down-regulation. Under the Dry treatment, the stimulation was about the same for cotton but much larger for wheat. Cotton growth was stimulated about 30% at both wet and Dry water levels, with lint yield being stimulated even more, up to 80% under wet and 50% under Dry. Wheat growth was stimulated less than that of cotton, about 20% at mid-season. Moreover, the final wheat grain yields increased only about 10% under Wet, whereas under Dry, the increase was about 20%. The FACE treatment had very little effect on the water use of cotton, but, for wheat, there appeared to be a small (4%) but significant reduction in water use, as determined by the soil water balance. Water use efficiency increased due to the larger growth and yields.

Water Relations of Differentially Irrigated Cotton Exposed to Ozone

AbstractThis field study was conducted to test the hypothesis that plants chronically exposed to O3 may be more susceptible to drought kcause OM3 typically inhibits root growth and increases shoot‐root ratios in plants. Cotton (Gossypium hirsutum L. cv. Acala SJ‐2) was grown in open‐top chambers on Hanford coarse sandy loam (coarseloamy, mixed, non‐acid, thermic, Typic Xerorthents) in Riverside, CA. Plants were grown under three irrigation regimes: optimum water for lint production (OW), suboptimum or moderate drought stress (SO), and severely drought stressed (SS) and were exposed to seasonal 12 h (0800–2000) O3 concentrations of 0.015, 0.074, 0.094, or 0.111 μL L−1. Leaf xylem pressure potentials (Ψ1) and soil water content (Ψv) were measured weekly from June to October. Mean seasonal Ψ1 increased from −1.89 MPa to −1.72 MPa in low to high O3 treatments, averaged across soil water regimes. Ozone had no effect on seasonal water use of cotton, but water use efficiency was significantly reduced by O3 in OW and SO, but noit in SS treatments. Drought‐stressed plants extracted proportionally greater amounts of water from deeper in the soil profile than OW cotton, and O3 had no apparent effect on this redistribution of roots in the soil. Since O3 had no apparent effect on the ability of droughtstressed cotton to maintain Ψ1 and to increase root growth relative to shoot growth, this suggests that O3 may have little or no effect: on the potential of cotton to adapt to or tolerate drought.