Water Use Efficiency Of Spring Wheat Research Articles

Long-Term Conservation Tillage Increases Yield and Water Use Efficiency of Spring Wheat (Triticum aestivum L.) by Regulating Substances Related to Stress on the Semi-Arid Loess Plateau of China

Improving the water-use efficiency (WUE) of crops is the most effective way to increase yields in semi-arid regions. Field research was carried out based on a long-term experiment initiated in 2001, aimed to explore the mechanisms of different tillage practices effects on grain yield and WUE of spring wheat. Tillage practices in the research including conventional tillage (CT), no tillage with no straw mulching (NT), conventional tillage with straw incorporation (TS), and no tillage with straw mulching (NTS). The effects of tillage practices on soil’s physical and chemical properties, dry matter accumulation, grain yield, dynamics of stress-related substances, and WUE were observed. Soil and plant samples in this research were collected in 2020 (wet year), 2021 (dry year), and 2022 (dry year). The results indicated that NTS improved the soil’s physical and chemical properties. The NTS treatment had the lowest soil bulk and pH and the highest total N, NO3--N, and available P. Throughout the whole growth stage, soil water content in the NTS and TS treatments were significantly higher than that of CT by 8.77–20.40% and 2.19–18.83, respectively. Averaged catalase (CAT), peroxidase (POD), and soluble protein across the three years with NTS and TS were significantly increased by 1.26–25.52% compared to CT. Meanwhile, the NTS treatment had the lowest malondialdehyde (MDA) content among the different tillage practices. NTS maintained the highest dry matter accumulation throughout the whole growth stage among different treatments; it was increased by 10.47–73.33% compared with CT. The average grain yields and WUE of NTS across the three years were 6.09–30.70% and 6.79–40.55% higher than other tillage practices, respectively. It is concluded that NTS influences dry matter accumulation and water-use efficiency during the whole growth stage of spring wheat by improving the soil’s physicochemical properties and modulating spring wheat substances related to stress, which in turn promotes yield formation.

Regulation of mulch conditions on photosynthesis and water utilization of spring wheat in northwest semi-arid area of China.

A field experiment was conducted from 2015 to 2016 in the northwestern Loess Plateau, China, to analyze the relationships among flag-leaf photosynthetic characteristics, water-consumption characteristics, and yield components of spring wheat (Triticum aestivum 'Longchun 35'). There were three treatments: whole-field plastic mulching (PMS), sand mulching (SM), and uncovered (CK). The results showed that soil-water storage levels at 0-300 cm of soil profile before wheat filling under PMS and SM treatments were greater than that in CK by 47.8 and 31.6 mm, respectively, while that under PMS was lower than CK by 15.6 mm at the filling stage. Water consumption under PMS and SM increased in the flagging-heading and flowering-filling stages compared with the CK. Leaf area indices under PMS and SM were increased by 59.0%-73.7% and 40.1%-52.7%, respectively, and leaf SPAD values were increased by 3.5%-28.4% and 2.9%-23.9%, respectively, compared with CK. The net photosynthetic rate of PMS was increased by 23.5%, 33.0% and 17.7% at the flagging, heading, and flowering stages. The corresponding stoma-tal conductance rate was increased by 32.6%, 76.4% and 66.9%, respectively. Net photosynthetic and stomatal conductance rates at the filling stage were decreased by 26.2% and 16.4%, respectively. At the heading, flowering, and filling stages, stomatal limitation values in PMS were decreased by 14.6%, 23.9% and 22.3%, respectively, and by 25.7%, 29.8% and 17.4%, respectively in SM. The instantaneous water-use efficiency of spring wheat in PMS was increased by 57.8% at the flagging stage and decreased by 11.2% at the flowering stage. At the heading and flowering stages, the apparent quantum efficiency was increased by 22.6% and 18.7% in PMS, and by 26.8% and 14.3% in SM, respectively. Plant height and yield component indices in PMS and SM were significantly greater than that in CK, with the enhancement being greater than that in dry years. Grain yield was increased by 36.2% and 8.7% and water-use efficiency increased by 9.4% and 3.4% in PMS and SM, respectively. PMS and SM treatments increased soil water storage before the pre-filling stage of wheat, aggravated water consumption during the flagging-shooting and flowering-filling stages, resulting in greater SPAD values and leaf area indices, which promoted the photosynthetic functions of flag leaves, facilitated sink formation and photosynthetic assimilate transportation, resulting in increased grain yields and water use efficiency of spring wheat. The effects of PMS treatment were more remarkable than those of SM in terms of increasing spring wheat's yield potential in wet years and adaptability in dry years.

Effects of drip irrigation levels on soil water, salinity and wheat growth in North China

Northwest China has long suffered from serious water scarcity and soil salinization. It is important to reduce the impact of soil salinization on crop growth and improve water-use efficiency (WUE) through efficient utilization of the limited water resources. This study examined the effects of drip irrigation (DI) on the water and salinity distribution in soil planted with spring wheat, a representative crop in Northwest of China. An in-depth analysis of the leaching of salts by irrigation water and salt accumulation in the soil profile was performed. An irrigation experiment with four irrigation levels (315 mm, 360 mm, 405 mm, and 450 mm) was conducted to investigate the effects of the amount of irrigation water (AIW) on the physiology and growth, photosynthesis, yield, and WUE of spring wheat. The results showed that applying the irrigation water at 405 mm can improve the distribution uniformity of soil water and WUE. Due to the leaching of salts by irrigation water, an increase in the AIW resulted in a higher desalination rate, a lower salt accumulation rate, and a greater depth of desalination. When the AIW was 315 mm, 360 mm, 405 mm and 450 mm, the average depth of desalination was 40 cm, 43 cm, 47 cm and 50 cm, respectively. The plant height, aboveground biomass, leaf area, and wheat ear mass varied significantly with the AIW. As the AIW increased, the average plant height increased, while the aboveground biomass, leaf area, and wheat ear mass increased first and then decreased. The net photosynthetic rate, transpiration rate, and stomatal conductance all increased greatly with increasing AIW, but excessive AIW could lower the net photosynthetic rate. The 405 mm treatment was the recommended irrigation level with the best wheat yield and water productivity at 7631.19 kg/hm2 and 1.88 kg/m3, respectively. Keywords: drip irrigation; spring wheat; spatial distribution; desalination; water use efficiency DOI: 10.25165/j.ijabe.20181101.3775 Citation: Wang Z H, Liao R K, Lin H, Jiang G J, He X L, Wu W Y, et al. Effects of drip irrigation levels on soil water, salinity and wheat growth in North China. Int J Agric & Biol Eng, 2018; 11(1): 146–156.

Adequate supply of potassium improves plant water‐use efficiency but not leaf water‐use efficiency of spring wheat

AbstractEnhancing crop water‐use efficiency (WUE) is a major research objective in water‐scarce agroecosystems. Potassium (K) enhances WUE and plays a crucial role in mitigating plant stress. Here, effects of K supply and PEG‐induced water deficit on WUE of spring wheat (Triticum aestivum L. var. Sonett), grown in nutrient solution, were studied. Plants were treated with three levels of K supply (0.1, 1, 4 mM K+) and two levels of PEG (0, 25%). WUE was determined at leaf level (WUEL), at whole‐plant level (WUEP), and via carbon isotope ratio (δ13C). Effects of assimilation and stomatal conductance on WUEL were evaluated and compared with effects of biomass production and whole‐plant transpiration (EP) on WUEP. Adequate K supply enhanced WUEP up to 30% and by additional 20% under PEG stress, but had no effect on WUEL. EP was lower with adequate K supply, but this effect may be attributed to canopy microclimate. Shoot δ13C responded linearly to time‐integrated WUEL in adequately supplied plants, but not in K‐deficient plants, indicating negative effects of K deficiency on mesophyll CO2 diffusion. It is concluded that leaf‐scale evaluations of WUE are not reliable in predicting whole‐plant WUE of crops such as spring wheat suffering K deficiency.

Effects of regulated deficit irrigation on grain yield and water use efficiency of spring wheat in an arid environment

Grain yield and water use efficiency (WUE) of spring wheat ( Triticum aestivum L.) in arid environments can be improved by applying irrigation selectively to allow soil water deficits to develop at non-critical stages of crop development. Field experiments were conducted on a loam soil in Zhangye district, northwest China in 2003 and 2004 to determine the grain yield, yield components, and water use characteristics of spring wheat in response to regulated deficit irrigation (RDI) schemes. Wheat grown under the RDI schemes produced 17% (in 2004) and 29% (in 2003) higher grain yield than wheat grown under water deficit-free control (5.6 t ha-1 in 2003 and 6.2 t ha-1 in 2004). Among six RDI schemes studied, wheat having a high water deficit at the jointing stage, but free from water def icit from booting to grain-filling produced highest grain yield in both 2003 (7.95 t ha-1) and 2004 (7.26 t ha-1). Compared with the control, wheat plants grown under the RDI schemes received 59 mm (or 15%) less water via irrigation, but they either extrac ted 41 mm more (or 74%) water from the soil profile (in 2003) or lowered (16%) evapotranspiration (ET) (in 2004). Grain yield increased as ET increased from 415 to 460 mm, and declined beyond 460 mm. The WUE values varied from 0.0116 to 0.0168 t ha-1 mm-1, and wheat grown under the RDI had 26% greater WUE compared with the control. Grain yield and WUE of spring wheat can be greatly improved by regulated deficit irrigation with reduced amounts of water. This practice is particularly valuable in arid regions where wheat production relies heavily on irrigation. Key words: