Highest Irrigation Water Use Efficiency Research Articles

Artificial Neural Network Modeling for Investigation on the Effect of Deficit Irrigation and Nitrogen Levels on Yield and Quality of Hay Remaining After Seed Harvest of Sorghum Sudangrass Hybrid

ABSTRACT This study aims to develop an Artificial Neural Network (ANN) modeling to be trained to forecast the effects of different irrigation water levels and fertilizer doses on the hay yield and some quality traits of herbal parts of Sorghum × Sudan grass hybrid (Sorghum sudanense vs. Sorghum bicolor). The ANN model was developed on the limited field experiments implemented in Bilecik, Turkey, for 2 years in 2021 and 2022. Experiments were conducted in split-plot design with three replications. In the study, three irrigation levels (I100, I60, and I30) were placed in the main parcels, and four fertilizer levels (N0, N50, N100 and N150 kg ha−1) were placed in the sub-parcels. Irrigations were made in three critical periods according to the amount of cumulative evaporation occurring in the Class A Pan. The results showed that irrigation and fertilization are important in terms of yield and quality characteristics. The yield increased depending on the irrigation and fertilization dose, and the highest value was obtained from the I100 × N150 interaction (28.10 t ha−1). The highest protein yield was determined from the I60 × N150 (2.37 t ha−1) interaction, and the Relative Feed Value (RFV) value was determined from the I30 × N150 (92.17) interaction. Irrigation Water Use Efficiency (IWUE) and Water Use Efficiency (WUE) values increased with decreasing irrigation amount, and the highest IWUE was determined from I30 and the highest WUE was determined from I60 irrigation subjects. According to the field experiments and ANN model, the I80 irrigation with 100 kg ha−1 nitrogen doses would suit the feed yield and quality of Sorghum × Sudan grass hybrid.

Productivity and energy-efficiency indices for diversified rice (Oryza sativa) based cropping systems in West Central Table Land Zone of Odisha

A long-term field experiment was conducted at Chiplima, Odisha, under irrigated medium land condition during 2006–07 to 2012–13, to evaluate the production potential and economics of 10 rice (Oryza sativa L.)-based crop ping systems. Rice–maize (Zea mays L.)–cowpea [Vigna unguiculata (L.) Walp.] and rice–groundnut (Arachis hypogaea L.)–bottle gourd [Lagenaria siceraria (Molina) Standl.] cropping systems recorded significantly higher average rice equivalent yield (19.55 and 18.57 t/ha, respectively) than the other systems evaluated, the relative production efficiency being 85.8 and 76.5% over the rice–groundnut system. Rice-based 3-cropping systems hav ing groundnut as winter (rabi) crop had higher land-use efficiency (83%). Rice–maize–cowpea recorded the high est irrigation water-use efficiency (230 kg REY/ha), whereas rice–groundnut–bottle gourd recorded the highest ap parent nutrient use efficiency (60.8 kg REY/kg NPK applied). Rice–maize–cowpea also recorded the highest en ergy-use efficiency (5.89), energy-output efficiency (1,240 MJ/ha/day) and energy productivity (0.34 kg REY/MJ). Rice–maize–cowpea had the highest employment generation efficiency (124.7%), followed by rice–groundnut bottle gourd (120.5%) and rice–groundnut–cowpea (120.0%). Rice–maize–cowpea gave the highest net returns of 135,087/ha, followed by rice–groundnut–bottle gourd system ( 111,777/ha). Rice–maize–cowpea system showed the highest system profitability ( 370/ha/day) and crop profitability ( 500/ha/day). This system also gave the highest benefit: cost ratio (2.56), with highest relative production efficiency (85.8%) and relative economic effi ciency (168.5%) compared to rice–groundnut system.

Cover crops and irrigation impacts on corn production and economic returns

Increases in irrigated crop acreage and frequent droughts during the growing season have caused continual groundwater decline of the Mississippi River Valley Alluvial Aquifer in the Mississippi Delta region. A field experiment was conducted from 2019 to 2021 to determine if combinations of irrigation scheduling thresholds and cover crops (CCs) could improve corn (Zea mays L.) production, water productivity (WP), irrigation water use efficiency (IWUE), and net returns. The irrigation thresholds used for irrigation scheduling were a wet threshold (−40 kPa), a dry threshold (−90 kPa), and no irrigation. The CC treatments were cereal rye (Secale cereale L.), hairy vetch (Vicia villosa R.), wheat (Triticum aestivum L.)-radish (Raphanus sativus L.)-turnip (Brassica rapa L.) mix, and no cover crop. In 2020, CCs reduced corn yield by 9–26% compared to no cover crop. In 2021, wet irrigation threshold treatments had 8% and 9% higher corn yield than no irrigation and dry irrigation threshold treatments, respectively. No irrigation treatments showed higher WP than dry and wet irrigation thresholds, while hairy vetch had higher in WP among CC treatments in year two of this study. Hairy vetch under the dry irrigation threshold had higher IWUE than all other treatments. The no-CC treatments generated $167, $340, and $58 ha−1 more under the wet, dry, and no irrigation treatments, respectively, when averaged over both years. Water conservation was affected by CC selection and irrigation management.

Assessment of Soil Water Dynamics and Yield Response of Broccoli Under Subsurface Drip Irrigation in the Semi-Arid Region of India

ABSTRACT A field experiment was conducted to investigate the optimum lateral spacing and irrigation frequency of a subsurface drip irrigation system for broccoli crop grown in the semi-arid region of Haryana (India). The effects on soil water dynamics, growth parameters (i.e. plant height, leaf length, no. of leaves/plant, curd weight and curd diameter), irrigation water use efficiency (IWUE), fertilize use efficiency (FUE) and yield response of broccoli were assessed under two lateral spacings (45 cm and 60 cm) and four irrigation frequencies (daily, and after one, two & three days) in the years of 2019–20 and 2020–21. The results show that soil moisture content was higher near the dripper, and it decreased with increasing radial distance from the drippers. Further, the moisture content was high at 45 cm lateral spacing as compared to 60 cm lateral spacing. The effects of selected treatments on growth and yield parameters were found significant and maximum broccoli yield (147. 41 q ha−1) was found at 45 cm lateral spacing with alternate days of irrigation. The highest IWUE and FUE of 9.93 kg/m3 and 30.68 kg/kg, respectively, were also found at alternate days irrigation with 45 cm lateral spacing. It may be concluded from the present study that alternate days irrigation with 45 cm lateral spacing is the best choice to obtain the maximum yield of broccoli grown in winter season in the semi-arid region of India.

Determination of drought tolerance of different strawberry genotypes.

Strawberry production future depends on productive, high quality and drought tolerant varieties. The goal of this study was to determine the most suitable variety by determining the yield and photosynthetic responses (net photosynthesis (Pn), stomatal conductance (gs), and transpiration rate (E)) of four strawberry genotypes with different characteristics (Rubygem, Festival; 33, and 59) at two different irrigation levels (IR50: water stress (WS), IR100: well-watered (WW)). It was also aimed to prepare the irrigation program by making use of the crop water stress index (CWSI). The trial was conducted at the Agronomic Research Area, University of Çukurova, Turkey during 2019-2020 experimental year. The trial was implemented as a 4 × 2 factorial scheme of genotypes and irrigation levels, in a split-plot design. Genotype Rubygem had the highest canopy temperature (Tc)-air temperature (Ta), whereas genotype 59 had the lowest, indicating that genotype 59 has better ability to thermoregulate leaf temperatures. Moreover, yield, Pn, and E were found to have a substantial negative relationship with Tc-Ta. WS reduced yield, Pn, gs, and E by 36%, 37%, 39%, and 43%, respectively, whereas it increased CWSI (22%) and irrigation water use efficiency (IWUE) (6%). Besides, the optimal time to measure leaf surface temperature of strawberries is around 1:00 pm and strawberry irrigation management might be maintained under the high tunnel in Mediterranean utilizing CWSI values between 0.49 and 0.63. Although genotypes had varying drought tolerance, the genotype 59 had the strongest yield and photosynthetic performances under both WW and WS conditions. Furthermore, 59 had highest IWUE and lowest CWSI in the WS conditions, proving to be the most drought tolerant genotype in this research.

Irrigation and nitrogen fertilization influence on alfalfa yield, nutritive value, and resource use efficiency in an arid environment

In arid regions, water and nitrogen are the two most limiting factors for sustainable pastoral production systems. In this study, we determined the potential effects of irrigation and nitrogen application on forage yield, nutritive values, and resource use efficiency of alfalfa in arid agro-climatic conditions. Field experiments were carried out using three irrigation regimes (W1, 300; W2, 450; and W3, 600 mm) and three nitrogen application rates (N1, 150; N2, 225; and N3, 300 Kg N ha−1). Alfalfa seeds were sown in fall 2014, uniformly managed for crop establishment, and subjected to different treatments in spring 2015–2016. Results indicated that irrigation, nitrogen, and their interaction (W × N) significantly (P ≤ 0.05) affected alfalfa forage yield, quality, irrigation water use efficiency (IWUE), and nitrogen use efficiency (NUE). Forage yield followed an increasing trend with increasing the irrigation amount at each harvest in both growing seasons. However, crude protein (CP), relative feed values (RFV), and IWUE were significantly decreased while neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents were increased at the high irrigation level (W3). The maximum forage yield was achieved with W3 treatment (25.9 and 23.1 t ha−1), followed by W2 (25.8 and 21.7 t ha−1) in 2015 and 2016. In both years, the highest IWUE (57.3 and 48.2 kg mm−1), CP (16.1 % and 17.7 %), and RFV (197.1 % and 186.2 %) values were achieved with W2 treatment. Moreover, increasing N application resulted in a linear decline in alfalfa forage yield, nutritive quality, and resource use efficiency. The maximum forage yield (24.4 and 21.2 t ha−1), CP (15.5 % and 16.4 %), RFV (210.3 % and 198.8 %), IWUE (54.3 and 47.0 kg mm−1), and NUE (169.9 and 141.2 kg kg−1), and lower ADF (25.7 % and 24.9 %) and NDF (31.0 % and 33.1 %) was obtained with application of 150 kg N ha−1 in 2015 and 2016. The regression equations of irrigation and nitrogen application indicated a quadratic relationship between yield and forage nutritive values. Overall, 450 mm irrigation coupled with 150 kg N ha−1 (W2N1) showed the most promising effects in terms of achieving optimal forage yield consistent with enhanced forage nutritive values, and greater resource use efficiency of alfalfa in the arid region of North China.

Maize response to irrigation and nitrogen under center pivot, subsurface drip and furrow irrigation: Water productivity, basal evapotranspiration and yield response factors

Information and data about quantification and comparison of crop water productivity indices for various irrigation levels and methods and nitrogen (N) application timings “simultaneously” under the same conditions do not exist. Unprecedented and extensive field experiments were conducted for maize (Zea mays L.) in 2016 and 2017 under center pivot (CP), subsurface drip irrigation (SDI) and furrow irrigation (FI) methods with full irrigation treatment (FIT), 80 % FIT, 60 % FIT and rainfed treatment (RFT) with three N application timings. N treatments were: (i) traditional (TN), (ii) non-traditional-1 (NT-1) and (iii) non-traditional-2 (NT-2). Irrigation-yield production functions (IYPF); evapotranspiration-yield production functions (ETYPF), basal evapotranspiration (ETb), crop water productivity (CWP), irrigation water use efficiency (IWUE); evapotranspiration water use efficiency (ETWUE) and yield response factors (Ky) were quantified for each treatment and irrigation method. SDI method required the least seasonal irrigation amount in achieving maximum yield, followed by CP (>~30 mm more than SDI) and FI (>~55 mm more than SDI). Average crop water requirement for achieving maximum grain yield varied among the N treatments within and between the irrigation methods. Irrigation amounts for achieving maximum yields were about 160, 175 and 175 mm in TN, NT-1 and NT-2 nitrogen treatments, respectively, in the CP method; 130, 150 and 150 mm in TN, NT-1 and NT-2 nitrogen treatments, respectively, in the SDI method; and 184 mm in TN management in the FI method. The highest grain yield production per 25.4 mm of applied irrigation followed the order of CP-TN (2.07 Mg ha−1)>SDI-NT-2 (1.91 Mg ha−1)>FI-TN (1.22 Mg ha−1). Across all treatments for the given irrigation method, the highest averaged CWP of 3.00 kg m−3 (slope = 0.067 kg m−3) was observed in the SDI method (p < 0.05) followed by 2.84 kg m−3 (slope = 0.052 kg m−3) in the CP method (p < 0.05) and 2.51 kg m−3 (slope = 0.046 kg m−3) in the FI method. The lowest ETb was observed in FI-TN (169 mm), followed by CP-NT-2 (172 mm) and SDI-TN (255 mm). For two consecutive years, N treatments did not have significant (p > 0.05) influence on IWUE in the CP or SDI methods. The highest IWUE, CWP and ETWUE were always obtained with limited irrigation treatments (60 % FIT and/or 80 % FIT) whereas the lowest with FIT. Maize under limited irrigation management had Ky < 1 with CP, SDI and FI along with lower Ky values than the respective TN treatment in CP and SDI, suggesting that the yield reduction is impacted to a lesser degree from the magnitude of water stress. The overall conclusion disclosed that utilizing the combination of limited irrigation (80 % FIT) with NT-1 fertigation under SDI and CP, while 80 % FIT under FI can be viable management practices for achieving high grain yield and CWP in conditions similar to those presented in this research.

Effects of irrigation and fertilization on different potato varieties growth, yield and resources use efficiency in the Northwest China

The scarcity of irrigation water has now become the main constraint for crop production globally. Potato growth in arid and semiarid regions is facing increasing challenges due to water deficit. Potato productivity is generally influenced by water and fertilizer, and the requirements for these factors vary depending on the soil type and potato variety. Field experiments were conducted during 2019–2020 to select the suitable potato varieties with the best combination of irrigation and fertilization levels. The three irrigation amounts were W1 (100% crop evapotranspiration (ETC)), W2 (80% ETC) and W3 (60% ETC). The three fertilizer rates were F1 (N–P2O5–K2O, 240–120–300 kg ha−1), F2 (180–90–225 kg ha−1) and F3 (120–60–150 kg ha−1). The three locally cultivated potato varieties were V1 (Feiurita), V2 (Xiapoti), and V3 (Yushu 4). The results showed that irrigation amount, fertilizer amount and potato variety had significant effects on potato growth, yield, quality and water and fertilizer productivity. The average potato yield and irrigation water use efficiency (IWUE) in Feiurita were 12.5% (11.9%) and 14.2% (13.3%) higher than those in Xiapoti in 2019 (2020), respectively. On average, the tuber yield and partial factor productivity (PFP) in W1 were 27.8% (35%) and 26.8% (34.7%) higher than those in W3 in 2019 (2020), respectively. Tuber yield, IWUE and polyphenol oxidase activity (POA) were most subject to irrigation amount, followed by potato variety and fertilizer rate. Potato tuber yield was significantly correlated with soil available potassium, soil actinomycete quantity, soil catalase activity, and soil sucrase activity (SSA). The W2F3V1 treatment had the highest PFP, starch content, reducing sugar content, and vitamin C content (VC), and the tuber yield and crude protein content were relatively high. The W3F2V1 treatment had the highest IWUE and vitamin C, and the starch content and POA were relatively high. Among them, the soil actinomycete quantity, soil cellulose decomposition bacteria quantity (SCDBQ), soil catalase activity, soil urease activity (SUA), and SSA in the W2F3V1 and W3F2V1 treatments were moderate. The W2F3V1 and W3F2V1 treatments are recommended as the best water and fertilizer management in sandy loam soils in Northwest China.

Impact of Partial Root Drying and Soil Mulching on Squash Yield and Water Use Efficiency in Arid

Practical and sustainable water management systems are needed in arid regions due to water shortages and climate change. Therefore, an experiment was initiated in winter (WS) and spring (SS), to investigate integrating deficit irrigation, associated with partial root drying (PRD) and soil mulching, under subsurface drip irrigation on squash yield, fruit quality, and irrigation water use efficiency (IWUE). Two mulching treatments, transparent plastic mulch (WM) and black plastic mulch (BM), were tested, and a treatment without mulch (NM) was used as a control. Three levels of irrigation were examined in a split-plot design with three replications: 100% of crop evapotranspiration (ETc), representing full irrigation (FI), 70% of ETc (PRD70), and 50% of ETc (PRD50). There was a higher squash yield and lower IWUE in SS than WS. The highest squash yields were recorded for PDR70 (82.53 Mg ha−1) and FI (80.62 Mg ha−1). The highest IWUE was obtained under PRD50. Plastic mulch significantly increased the squash yield (34%) and IWUE (46%) and enhanced stomatal conductance, photosynthesis, transpiration, leaf chlorophyll fluorescence, and leaf chlorophyll contents under PRD plants. These results indicate that in arid and semi-arid regions, soil mulch with deficit PRD could be used as a water-saving strategy without reducing yields.

Experimental Study on the Optimal Threshold of Water and Nitrogen Quantities for Tomato Growth under the Irrigation with Biogas Slurry in Greenhouse

HighlightsApplication of biogas slurry can significantly improve the integrated growth, yield, quality of tomatoes.Water-nitrogen coupling model was established based on multi-index evaluation system of tomatoes.The optimal application quantitative range of water and nitrogen was obtained based on the water-nitrogen coupling model.Abstract. Biogas slurry, a liquid organic fertilizer, has been widely used in agricultural production. However, the characteristics of high water content and low fertility make it always applied empirically and a scientific and reasonable application of biogas slurry is urgent needed in practical agricultural production. This study aims to explore the effects of various biogas slurry concentrations on the yield, comprehensive nutritional quality (CNQ), irrigation water use efficiency (IWUE) and partial factor productivity of nitrogen (PFPN) of tomatoes in a greenhouse. Seven treatments, including T1(BS1:4; 0.8Ep), T2 (BS1:6; 0.8Ep), and T3(BS1:8; 0.8Ep), T4(BS1:4; 0.6Ep), T5(BS1:4; 1.0Ep), CK (no fertilization; 1.0Ep), CF (conventional chemical fertilization; 1.0Ep) were set up, where BS1:4, BS1:6,and BS1:8 are the volume ratio of biogas slurry to water, 0.6, 0.8, and 1.0 were crop dish coefficients, respectively. Ep is the evaporation amount of a 20 cm standard evaporating dish. The results showed that appropriate application of biogas slurry had a positive impact on crop growth such as total dry biomass, plant height, stem diameter and finally increased the yields, in which T1 treatment was the best. The fruit yield increased with the increase of biogas slurry ratio for treatments at the same irrigation level of 0.8Ep and the maximum yield of single tomato can reach 5.174 kg. The IWUE increased with the decrease of irrigation for treatments at the same biogas slurry ratio of BS1:4 and T4 treatment had the highest IWUE. The CNQ first increased and then decreased with the increase of biogas slurry ratio under the same irrigation level of 0.8Ep and T2 treatment obtained the highest CNQ; but the PFPN decreased with the increase of biogas slurry ratio and T3 treatment acquired the largest PFPN. Within an 80% confidence interval, when the irrigation amount was in a range of 39.233~43.134 L and the nitrogen quantities was 7.983~8.426 g, the yield, IWUE, CNQ, and PFPN can reach =80% of their maximums at the same time. Taking into account the growth, yield, fruit quality, and water and fertilizer use efficiency, T1 treatment was the best fertigation strategy for a higher production and better quality. The results can provide some help for scientific management of biogas slurry application in greenhouse. Keywords: Biogas slurry, Quality, Spatial analysis method, Tomato (Lycopersicum esculantum Mill), Yield.

An Analytical View on Water Use Efficiency of Some Main Crops Grown in the Non-costal Parts of Thrace Region

The article contains data obtained from evaluations related to irrigation water use efficiency (IWUE) and water use efficiency (WUE), for the main crops, irrigated at different stages of growth, on the basis of some findings obtained in the Research Institute in Kırklareli. Each of the experimental crops was sown and farmed following procedures applied by the farmers in the region, except of the irrigation applications which were based on the sensitivity of a certain crop to water shortage in the soil, during the specific growth stages. Similar procedures were applied and all the experimental treatments were irrigated at growth stages, as predicted in the research methodology, and water amounts required to fill the 0-90 cm soil depth to field capacity were implied. Evaluation data obtained from the field experiments with three major crops, grown on the non-coastal lands of Thrace Region showed, that the productivity of irrigation water, as well as water use efficiencies of all analysed crops, are growth stage controlled. The highest IWUE and WUE efficiencies of 0.87 and 0.92 kg da-1 m-3; and 1.08 kg da-1 m-3 and 0.81 kg da-1 m-3; were determined for wheat and sunflower crops, irrigated at booting and flowering stages, respectively. Each m3 of irrigation water, applied during the most sensitive fruit formation stage (Ff) of pumpkin crop, provided additionally 8.47 kg da-1 fruit yield, 8.09 fruit numbers and 0.28 kg da-1 seed yields, more than those of rainfed farming (R).

Combined Application of Potassium and Zinc Improves Water Relations, Stay Green, Irrigation Water Use Efficiency, and Grain Quality of Maize under Drought Stress

Maize (Zea mays L.) plays an important role in the global food security, but its production is threatened by climate change, especially drought stress. Potassium (K) and zinc (Zn) are considered useful to mitigate the negative consequences of drought stress in plants. Therefore, the objective of this two-year study was to identify the best combination of K and Zn application to improve the water relations, photosynthetic pigments, yield, irrigation water use efficiency (IWUE) and grain quality of maize sown under mild and severe drought stress conditions. The consisted of three drought stress levels viz. 1) well-watered as control (WW), 2) mild drought (MD) with 25 mm of potential soil moisture deficit (PSMD), 3) severe drought (SD) with 50 mm of PSMD and six K-Zn treatments: i.e. 125, 100 and 150 kg ha−1 K with 0 and 12 kg ha−1 Zn. The results indicated that K-Zn application improved the water relations and chlorophyll contents, biological yield and grain quality, irrespective of water stress treatment. The combined application of K-Zn under mild drought stress produced statistically same biological yield and grain quality as under well-irrigated without K-Zn fertilization and also produced compratively higher IWUE, biological yield and grain quality under sverer drought stress. Hence, the application of K at 150 kg ha−1 in combination with Zn at 12 kg ha−1 might be useful to improve the maize production and grain quality under drought stress. As IWUE was low in WW conditions, therefore, irrigation scheduling must be re-evaluated for optimum water use efficiency.

Response Mechanism of Cotton Growth to Water and Nutrients under Drip Irrigation with Plastic Mulch in Southern Xinjiang

The effects of water and nutrient control measures on the cotton plant height, stem diameter, biomass, seed yield, and soil moisture under an irrigated plastic mulch production system were studied. Using field experiments in the 2018 cotton-growing season, 6 fertilization treatments (30-10.5-4.5 (N-P2O5-K2O), 24-8.4-3.6 (N-P2O5-K2O), 20-7-3 (N-P2O5-K2O), 16-5.6-2.4 (N-P2O5-K2O), 10-3.5-1.5 (N-P2O5-K2O), and 0-0-0 (N-P2O5-K2O) kg/mu) and 6 deficit irrigation treatments (40% PET, 60% PET, and 80% PET) were established at the cotton budding and flowering stages. Analysis of variance (ANOVA) (P&lt;0.05) was used to evaluate the significant differences among the treatments. The results showed that the effects of the water and nutrient control measures were obvious. The irrigation water use efficiency (IWUE) was the highest under the 80% deficit irrigation (T7) treatment at the flowering stage (2.62 kg/m3). Increases in cotton plant height and stem diameter were promoted by mild or moderate deficit irrigation at the flowering stage, but normal growth and development were affected by severe deficit irrigation at any growth stage. The growth indexes of cotton increased with increasing fertilization, but significant differences between each fertilization gradient were not obvious. At the same time, excessive fertilization not only had a positive effect on the LAI (leaf area index) and yield but also caused fertilizer waste and unnecessary cotton growth. The cotton seed yield and single boll yield reached their highest values (566 kg/mu) under the 1.2 times fertilizer treatment (T9), but the 0.8 times fertilizer treatment had the highest IWUE among the nutrient control treatments (1.91 kg/m3). Therefore, it is suggested that deficit irrigation at 60~80% of the potential evapotranspiration (PET) at the flowering stage and 16-5.6-2.4 (N-P2O5-K2O) fertilizer be applied as an optimal water and nutrient management strategy to maximize the seed cotton yield, IWUE, and overall growth and development of cotton.

Deficit Alternate Drip Irrigation Increased Root-Soil-Plant Interaction, Tomato Yield, and Quality.

To determine the soil mechanism in root-zone caused by water saving and the production response to alternate drip irrigation (ADI), the present study investigated the effects of deficit ADI on tomato growth using the conventional surface drip irrigation (CDI) as a control. The interactions among the experimental treatments on root index, photosynthetic efficiency, biomass accumulation, yield, fruit quality and irrigation water use efficiency (IWUE) were assessed and the inner mechanism of root-soil effecting on tomato growth, photosynthate distribution, yield and quality was discussed. ADI significantly enhanced root-soil interaction, promoted soil nitrogen and phosphorus absorption by tomato and tomato growth. However, different soil moisture deficits significantly affected tomato photosynthate accumulation and distribution, as well as fruit quality. With irrigation amount of 50% field capacity (F), ADI significantly increased soluble sugar, total soluble solid and lycopene by 38.08%, 19.48% and 30.05%, respectively, compared to those of CDI, but decreased irrigation amounts by 29.86% in comparison with the CDI one. ADI of 70% F could significantly distribute more photosynthate to fruits, thus enhanced tomato yields by 24.6% and improved IWUE by 17.05% compared to that of CDI. In addition, ADI of 70% F improved tomato fruits quality, and in particular organic acid was decreased by 43.75% and sugar-acid ratio was increased by 97% compared to CDI. However, ADI of 60% F distributed more photosynthate to plant, showing no significant difference of yields in comparison with CDI and ADI of 70% F, but a higher IWUE by 19.54% than that of CDI. ADI of 60% F significantly enhanced soluble sugar, total soluble solid, soluble protein, lycopene and sugar-acid ratio in tomato fruits by 2.06, 1.26, 1.61, 1.4 and 3.2 times respectively compared to CDI. Therefore, ADI of 60% or 70% F can be overall recommended for tomato production in a greenhouse, plant growth, fruit yield and quality, and IWUE.

Irrigation and Planting Geometry Effects on Cotton (Gossypium hirsutum L.) Yield and Water Use

Addressing the challenges of dwindling groundwater resources and ever-increasing demands for water necessitate enhancing water use efficiency (WUE) in irrigated agriculture. In a 2-year study, we examined the effects of different levels of irrigation and PG on lint yield and WUE of furrow irrigated cotton in a Dundee silt loam in the Mississippi Delta. The main plots were three irrigation regimes: irrigating every furrow (FI), alternate furrow (HI), and no irrigation (RF) and subplots were two planting geometries (PG): single-row (SR) and twin-row (TR). Across FI and HI no significant differences were observed in plant height and biomass yield at flowering, but chlorophyll content index and leaf area index (LAI) were positively affected. Canopy closure in TR planting occurred earlier than SR leading to higher leaf areas available for harvesting more light during photosynthesis. Averaged across the irrigation regimes, the TR planting enhanced lint yield by 10.6% in 2018 and 17.6% in 2019 compared to SR. The average lint yield in SR and TR were: 1779 and 2028 kg ha-1 under FI, 1803 and 2082 kg ha-1 under HI, and 1573 and 1788 kg ha-1 under RF treatments, respectively. In FI and HI treatments, TR had higher lint yield than RF treatment by 13.8% and 16.5%, respectively. Lint yield in HI with TR had the highest irrigation WUE (3.4 kg ha-1 mm-1) followed by HI with SR (2.7 kg ha-1 mm-1). These results demonstrated that cotton grown in TR with HI could reduce irrigation water demand in silt loams.

Onion growth, yield and quality as influenced by different drip lateral depths and irrigation levels

This research aimed to evaluate the different lateral depths and irrigation water applied with subsurface drip irrigation on onion production traits during the spring growing seasons of 2009 and 2010 in Tekirdag conditions. Three different lateral depths as 0 (surface drip), 10 and 20 cm (subsurface drip) and four different irrigation (50, 75, 100 and 125% of Class A pan evaporation). The seasonal evapotranspiration ranged from 337.1 and 715.4 mm depending on irrigation water applied. The highest onion yield obtained in the treatment which lateral was buried in 20 cm depth and the amount of irrigation water was applied based on 125% of Class A pan evaporation. It can be said that the total marketable onion yield increases as the amount of lateral depth and applied irrigation water increases. The irrigation water use efficiency (IWUE) changed from 4.03 to 18.30 kg m−3 while the water use efficiency (WUE) changed from 2.61 to 6.86 kg m−3. The highest IWUE and WUE obtained in the treatment which lateral was buried in 20 cm depth and the amount of irrigation water was applied based on 50% of Class A pan evaporation.

ACCLIMATIZATION FODDER BEET PLANTS UNDER TWO IRRIGATION SYSTEMS IN SALINE SOILS AT SAHL EL-TINA - NORTH SINAI

Soil salinity is a major problem in Egypt where salt affected lands are increasing over the productive farmland. Fodder beet plant (Beta vulgaris L. Monovert) could be a potential fodder crop for small ruminants based on its moderate nutritive value and high biomass production and its ability to grow in high salt affected soils. The aim of this study was to evaluate for fodder beet yield under traditional management practices (TMP) and improved management practices (IMP). The TMP included the practices carried out by the farmers and the other one (IMP) included the integrated practices of modified irrigation systems with applied leaching requirements, suitable planting method, application of appropriate rate of fertilization (NPK) and addition of sulfur, farmyard manure (FYM) and effective micro-organisms solution (EM). Two field experiments were conducted in farmers’ fields under saline conditions of Sahl El-Tina area in 2010/2011& 2011/2012 winter seasons. The treatments of both experiments included two irrigation systems (permanent sprinkler “PS” and surface furrows “FI”), two management practices (traditional and improved), and two planting methods (one side and two sides of the ridge). The treatments were arranged in completely randomized blocks design with four replicates. The obtained results indicated that the IMP decreased soil salinity and increased water use efficiency, under modified irrigation system. Based on the results of two growing seasons, irrigation water use efficiency (IWUE) were the highest average values as 11.47 and 16.22 kg m-3 obtained with IMP&FI and IMP&PS treatments, respectively. Developed furrow irrigation with improved management practices resulted in higher IWUE by 23.4%. While, modified sprinkler irrigation system with improved management practices led to increase in IWUE by 17.9%. It is clear that application of IMP significantly increase of growth characters, fresh yield (leaves and roots) of fodder beet by 5% as compared to the TMP. Consequently, sustainable development can be achieved by application IMP for mitigate soil salinity hazards and enhance the productivity of fodder beet as forage crops in Sahl El-Tina area, North Sinai to solve the feed shortage problem around the year.

Participatory Irrigation Management and Irrigation Water Use Efficiency in Maize Production: Evidence from Zhangye City, Northwestern China

Water has become increasingly scarce in northwestern China due to climate change, economic growth and burgeoning population. Improving agriculture water use efficiency is of strategic significance in promoting socio-economic water productivity for arid and semi-arid inland river basins. Based on the household-level data collected in Zhangye City, which is located in the middle reaches of Heihe River Basin (HRB) in northwestern China, irrigation water use efficiency (IWUE) of maize is estimated based on stochastic frontier analysis. The impacts of influential factors, especially the participatory irrigation management (PIM) through water user associations (WUAs), on IWUE were further examined. Results show that the estimated average Technical efficiency (TE) and IWUE of maize production are 0.74 and 0.24, respectively. The participation level in irrigation management is very low, with only 40% of the respondents participating in WUA meetings. In addition, most have a relatively superficial understanding of the roles and management scheme of WUAs. Empirical results show that though significantly positive, the magnitude of the impact of PIM on IWUE is relatively small. Households that participated in WUA meetings achieved only 0.002% higher IWUEs than those have never participated in. WUAs are not operating with their designed objectives. Consequently, reform of the traditional management form of WUAs to make them more transparent, fair, and extensively participated in among farmers is in urgently need. In addition, we also find that water price, source of irrigation water, irrigation technology adoption and famers’ education level and farming experience also have significant positive impacts on IWUE.

Evaluation of yield, quality and crop water stress index of sugar beet under different irrigation regimes

This study was carried out to evaluate the use of the crop water stress index (CWSI) for irrigation scheduling of sugar beet for two years under the semi arid climate of Iran. Statistical relationships between CWSI and yield, quality parameters and irrigation water use efficiency (IWUE) were investigated. Irrigations were scheduled based on 100 (I100), 85 (I85), 70 (I50) and 0% (I0) of plant water requirement. CWSI values were calculated from the measurements of canopy temperatures by infrared thermometer, air temperatures and vapor pressure deficit values for all the irrigated treatments. The highest IWUE was found in I70 with 9.16 and 1.66 kg m−3 for the root and sugar yield, respectively, in 2013. A non-water stressed baseline (lower line) equation for sugar beet was measured from full irrigated plots as (Tc − Ta)ll = −0.832VPD + 2.1811; R2 = 0.6508. There was a high determination coefficient between CWSI with the root and sugar yield and IWUE. The CWSI could be used to determine the irrigation time of sugar beet, and 0.3 could be offered as a threshold value. Results indicated that the CWSI can be used to evaluate crop water stress and improve irrigation scheduling for sugar beet under semiarid conditions.

Soil moisture distribution under drip irrigation and seepage for potato production

Keeping soil moisture content at field-capacity in the root zone tends to maximize crop yield. However, this is challenging in sandy soils with a shallow water table and low water holding capacity. Seepage irrigation (SEP) relies on capillarity water movement from a water table to irrigate the crop, creating uneven soil moisture distribution across the field, which could be improved with drip irrigation. The objectives of this study were to evaluate irrigation water use efficiency (IWUE) for potatoes and soil moisture distribution uniformity of two drip tape installation depths (surface at 0.05m, SUR and subsurface at 0.15m, SUB) as an alternative method to SEP. The design of the experiment was a randomized complete block with irrigation treatments as main plots, and potato varieties (Atlantic, Fabula, and Red LaSoda) as subplots. The volume of water applied, water table level, and soil volumetric water content were continuously measured for two seasons, 2011 and 2012. Drip irrigation significantly increased the moisture distribution uniformity in the potato ridge. The majority of the plant root system was concentrated in the upper soil layer (∼0.3m), regardless of irrigation treatment. Similar marketable yield between SUR and SEP were achieved for Fabula and Atlantic in the first season, while lower yields were reported for Red LaSoda under drip in both years. The SUB produced lower yield in both years attributed to limited water capillarity. Drip irrigation reduced water use 48% and 88% in 2011 and 2012, respectively. Higher IWUE was obtained with drip compared to SEP for all varieties in 2012. The SEP used more irrigation water to supply the crop than SUR resulting in a difference in IWUE of 5.7kgm−3. The SUR was capable of adequately irrigating the potato shallow root producing similar yield to SEP for Atlantic and Fabula varieties.