Effects Of Irrigation Water Salinity Research Articles

EMERGENCE, GROWTH, AND PRODUCTION OF COLORED COTTON SUBJECTED TO SALT STRESS AND ORGANIC FERTILIZATION

ABSTRACT The semi-arid region of Northeast Brazil is vulnerable to problems of water scarcity and salinity, resulting in low-quality irrigation water and the need to adopt cultivation strategies that make the production system viable. Given the above, this study aimed to evaluate emergence, growth, and production of colored cotton subjected to increasing levels of irrigation water salinity and organic matter doses. The experiment was carried out in a eutrophic Regolithic Neosol with a sandy loam texture in a greenhouse in the municipality of Campina Grande - PB, Brazil. A randomized block design was used in a 4 x 4 factorial scheme with three replicates, and the treatments corresponded to four levels of electrical conductivity of water - ECw (1.7, 3.4, 5.1, and 6.8 dS m-1) and four doses of organic matter - OM (0, 2.5, 3.5, and 4.5% based on soil volume). Increasing irrigation water salinity with ECw values above 1.7 dS m-1 reduced emergence, growth, and production of colored cotton, and the cotton seed weight was the variable most affected by salinity. Organic matter addition led to increased cotton growth and production, especially in terms of seed weight. Increasing doses of organic matter attenuated the effect of irrigation water salinity on the number of bolls in ‘BRS Jady’ cotton.

Yield of green beans subjected to continuous and pulse drip irrigation with saline water

ABSTRACT In view of the imminent need for efficient water use and the search for adequate management techniques to reduce the effect of salinity on plants, a study was conducted to evaluate the effect of continuous and pulses drip irrigation with saline water on green bean yield and water use efficiency. The experiment was conducted in a greenhouse, in a completely randomized design, with treatments distributed in a 2 x 5 factorial arrangement. The first factor was type of drip irrigation, i.e., continuous or pulse, while the second factor was the levels of water salinity (electrical conductivity of 0.3, 1.5, 2.5, 3.5 and 4.5 dS m-1), with five replicates, and two plants per replicate, totaling 50 experimental units. The following variables were analysed: production of pods per pot, water use efficiency and the electrical conductivity of the soil saturation extract. According to the results, significant effect of the interaction and decreasing linear fits in response to salinity occurred for all variables studied. It was possible to note that pulse drip irrigation reduced the negative effects of irrigation water salinity on green bean yield and increased water use efficiency.

Effects of irrigation water salinity on soil salt content distribution, soil physical properties and water use efficiency of maize for seed production in arid Northwest China

In order to explore the use of groundwater resources, field experiments were conducted for three consecutive years during 2012-2014 in the Shiyang River basin of Northwest China. Irrigation was conducted using four different water salinity levels that were arranged in a split plot design. These four water salinity levels were s0, s3, s6 and s9 (0.71, 3, 6 and 9 g/L, respectively). The soil salt content, soil bulk density, soil porosity, saturated hydraulic conductivity, plant height, leaf area index and yield of maize for seed production were measured for studying the effects of saline water irrigation on soil salt content distribution, soil physical properties and water use efficiency. It was observed that higher salinity level of irrigation water and long duration of saline water irrigation resulted in more salt accumulation. Compared to initial values, the soil salt accumulation in 0-100 cm soil layer after three years of experiments for s0, s3, s6 and s9 was 0.189 mg/cm3, 0.654 mg/cm3, 0.717 mg/cm3 and 1.135 mg/cm3, respectively. Both greater salt levels in the irrigation water and frequent saline water irrigation led to greater soil bulk density, but poorer soil porosity and less saturated hydraulic conductivity. The saturated hydraulic conductivity decreased with increase in soil bulk density, but increased with improvement in soil porosity. It was noted that the maize height, leaf area index and maize yield gradually decreased with increase in water salinity. The maize yield decreased over 25% and the water use efficiency also gradually declined when irrigated with water containing 6 g/L and 9 g/L salinity levels. However, maize yield following saline water irrigation with 3 g/L decreased less than 20% and the decline in water use efficiency was not significant during the three-year experiment period. The results demonstrate that irrigation with saline water at the level of 6 g/L and 9 g/L in the study area is not suitable, while saline water irrigation with 3 g/L would be acceptable for a short duration together with salt leaching through spring irrigation before sowing. Keywords: saline water irrigation, soil salt content distribution, soil physical properties, maize for seed production, water use efficiency DOI: 10.25165/j.ijabe.20181103.3146 Citation: Yuan C F, Feng S Y, Wang J, Huo Z L, Ji Q Y. Effects of irrigation water salinity on soil salt content distribution, soil physical properties and water use efficiency of maize for seed production in arid Northwest China. Int J Agric & Biol Eng, 2018; 11(3): 137–145.

EFFECT OF SALICYLIC ACID APPLICATION ON THE GROWTH AND ACTIVE CONSTITUENTS OF FENNEL PLANTS UNDER SALINITY STRESS CONDITIONS

Nowadays, Egypt faces a problem in the amount of available irrigation water because the Egyptian water quota is fixed, thus the cornerstone of the current Egyptian strategy is increasing crop productivity from unit area with the lowest possible amount of irrigation water. So, a pots experiment was carried out at the Experimental Farm, Faculty of Agriculture, Menoufia University, Shebin El-Kom, Egypt (30.52oN and 30.99oE) during two successive growth winter seasons, i.e. 2013/2014 and 2014/2015 to study the effect of different rates of salicylic acid (SA), different salinity levels of irrigation water and their interactions on growth, yield and chemical compositions of fennel plants (Foeniculum vulgare, Mill.), variety of purple-bronze foliage grown on clayey-textured soil. SA was added as foliar applications at four rates namely 50, 100, 150 and 200 (mg/l) in addition to control treatment with SA-free water. The water used for irrigation (artificial water) has EC of 3, 5 and 7 (dS m-1) for W2, W3 and W4 respectively, beside Nile water (W1) which is characterized by EC of 0.37 dSm-1. The design of the experiment is a complete randomized block with three replicates. In two growing seasons, a vegetative growth characters, i.e. plant height (cm), number of main branches/plant and fresh weight of whole plant (g) as well as yield parameters, i.e. number of umbels/plant, fresh and dry weights of umbels/plant (g), weight of 100 fruits (g/plant) and fruit yield (g/plant), chemical composition together with volatile oil percentage, oil constituents, photosynthetic pigments, N, P, K and total carbohydrate contents were estimated of fennel plants. The obtained results indicated that, all vegetative growth characters and yield parameters were significantly reduced with increasing salinity levels of irrigation water, excluding those irrigated by W2 level, in which slight increments in all of studied criteria were induced. Also, chlorophyll a and b contents followed the same order, where the highest decrease in values was observed in plants irrigated by W4 level either individually or together with SA compared to control treatment. Contents (%) of N, P and K were reduced with increasing salinity levels. While carotenoids, volatile oil and total carbohydrate contents (%) were gradually increased with increasing salinity levels, especially in those irrigated by W3 level. Foliar spraying with different SA concentrations could have alleviated the harmful effect of salinity stress and was associated with high significant values in the most traits under study. Interactions betweensalinity levels of irrigation water and SA concentrations appeared to be the most effective on growth and yield parameters especially when fennel plants irrigated with W2 level and spraying with SA at 150 mg/l. Generally, the results of this study concluded that, under-irrigation by using saline water, salicylic acid should be used as foliar application especially at rate 150 mg/l to reduce the hazardous effects of irrigation water salinity on both quantity and quality of fennel plants.

Intercropping Halophytes to Mitigate Salinity Stress in Watermelon

Saline irrigation water can lead to salt buildup and reduced crop yields. Halophytic plants are known to accumulate excess salts in tissues, removing them from the immediate environment. This two-phase experiment explored the feasibility of intercropping watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai var. lanatus) with halophytic species to mitigate the negative effects of saline irrigation water while providing a value-added crop. In the first experiment, six greenhouse-grown species were irrigated with water that was either deionized (0 dS m−1) or contained 3 or 6 dS m−1 of salts for 41 days and screened for growth and salt removal. Two halophytes were selected to be additively intercropped with watermelon under field conditions and irrigated with the same saline irrigation levels as the first experiment. Results indicated that garden orache (Atriplex hortensis L.) exhibited the highest growth rates and purslane (Portulaca oleracea L.) accumulated high amounts of sodium in plant tissues under saline irrigation. The field experiment showed that watermelon yields, stem water potential, and fruit quality were not affected by saline irrigation; however, the watermelon/orache intercropping treatment had significantly higher yields. These results suggest intercropping with halophytes has the potential to contribute a value-added crop without reducing watermelon yields.

Improvement of Nitrogen Fertilization Practices for Efficient Use by Wheat Irrigated With Saline Water under Mulching Using 15N Technique

A FIELD experiment was carried out to investigate the effects of saline irrigation water and soil mulching on the growth and yield of cultivated wheat crop. Wheat yield for nonmulched treatment irrigated by fresh water (3366 kg.ha-1) was higher than the mulched one irrigated with fresh water (3227 kg.ha-1) and also higher than both mulched and non-mulched treatments irrigated by saline water of 6 and 8 dS.m-1. Under non-mulched condition, the treatment of the irrigated by 6 dS.m-1 recorded a higher production of2411 kg.ha-1 than those irrigated by 8 dS.m-1 (2231 kg.ha-1). In thesame sequence mulched treatment of the irrigated by 6 dS.m-1 recorded a higher yield (2936 kg ha-1) than the mulched one irrigated by 8 dS.m-1(2573 kg.ha-1).The nitrogen uptake by grain of wheat irrigated by fresh water and non-mulching treatments was much better thanthat in mulching treatments, but, mulching treatment combined with saline water (6, and 8 dS.m-1) was much better than non-mulched one. Similar trend was noticed with N uptake by straw.Proportion and absolute values ofNitrogen derived from fertilizer(Ndff) as well as nitrogen use efficiency (NUE)gained by grains or straw were severely reduced by increasing water salinity level as compared to those irrigated with fresh water. Mulching has a positive effect on combating salinity stress. It seems that, in general, mulching made the plants more able to derive more nitrogen from fertilizer and improved NUE. Nitrogen derived from fertilizer by grains was significantly higher than those of straw. Similar trend was noticed for NUE.

Responses of Different Panicum miliaceum L. Genotypes to Saline and Water Stress in a Marginal Mediterranean Environment

The aims of this study were to evaluate: (1) the effect of sodium chloride (NaCl) and mannitol at different osmotic pressures on the germination of three proso millet (Panicum miliaceum L.) genotypes (VIR 9181, Unikum, and Kinelskoje) under controlled laboratory conditions; and (2) the effects of irrigation water salinity, maximum crop evapotranspiration (ETm) restitution regimes, and arbuscular mycorrhizal fungi (AMF) inoculation on forage production in a marginal Mediterranean soil for the genotypes that showed the highest and lowest seed germination. In the laboratory experiment, the Unikum genotype showed the highest seed germination (95.1%), whereas the lowest was found for Kinelskoje (80.4%). Regardless of the osmoticum type, germination was significantly reduced by osmotic pressure increases. Unikum showed a higher fresh biomass yield (FBY) (620.4 ± 126.3 g m−2) than Kinelskoje (340.0 ± 73.5 g m−2). AMF inoculation did not influence FBY under salt conditions, while in the absence of salt conditions it significantly increased the Unikum FBY (+50.7%) as compared to the uninoculated treatment (552.5 ± 269 g m−2). The 25% ETm significantly reduced FBY in both genotypes (−86.2% and −84.1% for Unikum and Kinelskoje, respectively) sd compared to the 100% ETm treatments (1090.3 ± 49.7 g m−2 in Unikum and 587 ± 72.2 g m−2 in Kinelskoje). The obtained results give novel information about proso millet forage production in low-input agriculture in marginal semi-arid Mediterranean land.

Effects of irrigation water salinity on soil salt content distribution, soil physical properties and water use efficiency of maize for seed production in arid Northwest China

In order to explore the use of groundwater resources, field experiments were conducted for three consecutive years during 2012-2014 in the Shiyang River basin of Northwest China. Irrigation was conducted using four different water salinity levels that were arranged in a split plot design. These four water salinity levels were s0, s3, s6 and s9 (0.71, 3, 6 and 9 g/L, respectively). The soil salt content, soil bulk density, soil porosity, saturated hydraulic conductivity, plant height, leaf area index and yield of maize for seed production were measured for studying the effects of saline water irrigation on soil salt content distribution, soil physical properties and water use efficiency. It was observed that higher salinity level of irrigation water and long duration of saline water irrigation resulted in more salt accumulation. Compared to initial values, the soil salt accumulation in 0-100 cm soil layer after three years of experiments for s0, s3, s6 and s9 was 0.189 mg/cm3, 0.654 mg/cm3, 0.717 mg/cm3 and 1.135 mg/cm3, respectively. Both greater salt levels in the irrigation water and frequent saline water irrigation led to greater soil bulk density, but poorer soil porosity and less saturated hydraulic conductivity. The saturated hydraulic conductivity decreased with increase in soil bulk density, but increased with improvement in soil porosity. It was noted that the maize height, leaf area index and maize yield gradually decreased with increase in water salinity. The maize yield decreased over 25% and the water use efficiency also gradually declined when irrigated with water containing 6 g/L and 9 g/L salinity levels. However, maize yield following saline water irrigation with 3 g/L decreased less than 20% and the decline in water use efficiency was not significant during the three-year experiment period. The results demonstrate that irrigation with saline water at the level of 6 g/L and 9 g/L in the study area is not suitable, while saline water irrigation with 3 g/L would be acceptable for a short duration together with salt leaching through spring irrigation before sowing. Keywords: saline water irrigation, soil salt content distribution, soil physical properties, maize for seed production, water use efficiency DOI: 10.25165/j.ijabe.20181103.3146 Citation: Yuan C F, Feng S Y, Wang J, Huo Z L, Ji Q Y. Effects of irrigation water salinity on soil salt content distribution, soil physical properties and water use efficiency of maize for seed production in arid Northwest China. Int J Agric & Biol Eng, 2018; 11(3): 137–145.

Sugar beet yield response to different levels of saline irrigation water and leaching in an arid region

ABSTRACTThe main objective of this work was to evaluate the effects of saline irrigation water and leaching on the sugar beet yield components. In a field experiment in Rudasht region (Isfahan, Iran), three irrigation water salinity levels (1.6, 8.1, and 12.3 dS m−1) and with/without leaching were applied. The experimental units comprised of a completely randomized block design, with split plot in four replications. The results indicated that the white sugar yield and alkalinity decreased by increasing the water salinity. Salts leaching significantly increased the root yield, white sugar yield, and white sugar concentration. With higher levels of water salinity molasses sugar, leaf weight, and the concentrations of Na, K, and α- amino-N in sugar beet significantly increased. Consequently, it appears that the use of drainage water in combination with fresh water could be recommended as a strategic management way to grow sugar beet in the investigated arid region.

Interactive effects of saline irrigation water and genotypes on nutrient composition of chamomile (Matricaria Recutita L.)

ABSTRACTThis study was conducted to elucidate the effect of salinity (2, 6, 9, and 12 dS m−1 sodium chloride (NaCl)) on three Iranian German chamomile genotypes (Shiraz, Ahvaz, and Isfahan). The Shiraz and Ahvaz genotypes, respectively, had the highest productivity and tolerance level, while the Isfahan was the less salt-tolerant genotype. In contrast to quantitative traits, the Isfahan genotype exhibited superior qualitative traits in terms of essential oil and chamazulene percentage. The differential responses to productivity and salt-resistance were attributed to the genetic variation, higher root to shoot ratios, and compartmentalization of sodium in roots of the Shiraz and Ahvaz genotypes, leading to better nutrient uptake and balance. While the nutrient composition was relatively in the same range for all genotypes, the higher accumulation of phosphorus in root and anthodia of the Shiraz genotype was evident. In addition, anthodia of the Ahvaz and root of the Shiraz genotype stored more nitrogen nutrient element.

Effects of saline water irrigation on soil salinity and yield of summer maize (Zea mays L.) in subsurface drainage system

Sustainable development of saline water irrigation was restricted by salt accumulation in the soil profile without appropriate salt discharging measures. A two year study was conducted in 2014 and 2015 to identify the effect of saline water irrigation on soil salt and maize yield under subsurface drainage system. The treatments of this study comprised three levels of water salinity with 0.78, 3.75, and 6.25dSm−1 (S1–S3) and three levels of subsurface drainage depth with no subsurface drainage, drain depth of 0.8m and 1.2m (D0–D2). Results indicated that the average salt content within the root zone was in the order of D0>D2>D1. No salt accumulation occurred during the two growing seasons under D1, but there was salt accumulation under D2S3. Soil desalinization efficiency reduced with the increasing of irrigation water salinity, and the average desalinization efficiency for D1 was higher than that of D0 and D2. Maize yield and water use efficiency decreased with the increase of water salinity. The yield decreased by 2.08–3.01% for every 1dSm−1 increase in salinity level of irrigation water under D1, and 3.53–3.93% for every 1dSm−1 under D2. The effects of water salinity and drainage depth on maize yield and WUE were significant (p<0.05) in the two growing seasons. From the view points of relative yield and soil salt balance, it can be recognized even as the salinity level of irrigation water is as high as 6.25dSm−1, saline water can be applied to irrigate maize under drain depth of 0.8m.

Effects of irrigation water salinity on evapotranspiration modified by leaching fractions in hot pepper plants

We investigated whether leaching fraction (LF) is able to modify the effects of irrigation water salinity (ECiw) on evapotranspiration (ET). We conducted an experiment with a completely randomized block design using five levels of ECiw and two LFs. Results showed that the electrical conductivity of drainage water (ECdw) in an LF of 0.29 was considerably higher during the 21–36 days after transplanting (DAT), and considerably lower after 50 DAT than in an LF of 0.17. The hourly, nighttime, daily, cumulative and seasonal ET all decreased considerably as a result of an increase in the ECiw. The daily ET started to be considerably higher in the LF of 0.29 than in the LF of 0.17 from 65 DAT. Compared with the LF of 0.17, the seasonal ET in the LF of 0.29 under various ECiw levels increased by 4.8%–8.7%. The Maas and Hoffman and van Genuchten and Hoffman models both corresponded well with the measured relative seasonal ET and the LF had no marked effects on these model parameters. Collectively, an increase in the level of ECiw always decreased the ET substantially. An increase in the LF increased the ET considerably, but there was a time lag.

Response of Hot Pepper Yield, Fruit Quality, and Fruit Ion Content to Irrigation Water Salinity and Leaching Fractions

It has been proved that irrigation with high saline water and leaching fraction (LF) affect crop yield, but the effects of irrigation water salinity (ECiw) and LF on fruit quality remain largely elusive. We therefore investigated the effects of ECiw and LF on the yield, fruit quality, and ion content of hot peppers. An experiment using irrigation water with five levels of salinity (ECiw of 0.9, 1.6, 2.7, 4.7, and 7.0 dS·m−1) and two LFs (0.17 and 0.29) was conducted in a rain shelter. The experiment took the form of a completely randomized block design, and each treatment was replicated four times. We increased the salinity of the irrigation water by adding 1:1 milliequivalent concentrations of NaCl and CaCl2 to a half-strength Hoagland solution. The plants were irrigated for 120% and 140% evapotranspiration, corresponding to an LF of 0.17 and 0.29. Results showed that the total fruit yield decreased significantly with an increase in the ECiw as a result of reduction both in the fresh weight of fruit and the number of fruit per plant. An increase in the ECiw also led to a decrease in the total dry biomass of fruit and plant, as well as decreasing water use efficiency (WUEF). Salinity reduced the appearance of the fruit by both decreasing the length (FL) and maximum width (FMW) of the fruit. However, increased ECiw also improved the taste of the hot peppers by increasing the total soluble solid (TSS) content, as well as adding to their nutritional quality with a higher content of Vitamin C (VC). Their storage quality was also improved because of an improvement in the firmness of the fruit (Fn) as well as a reduction in the fruit water content (FWC). An increase in the LF led to an increase in the total fruit yield, total dry biomass of fruit and plant, and WUEF; it also increased the FWC and VC content, and decreased the FMW and fruit shape index (FSI). The threshold-slope linear response and sigmoidal-sharp models were both a good fit for the measured total fruit yield, and the LF had no significant effect on the model parameters. The relative TSS and Fn increased linearly as the electrical conductivity (EC) of soil-saturated paste extract (ECe) increased, whereas they decreased linearly as the relative seasonal evapotranspiration (ETr) increased regardless of the LFs. The relative FW, FL, and FMW decreased linearly with the increased ECe, and increased linearly with the increased ETr regardless of the LFs. The relative fruit Na+ concentration increased linearly as the ECe increased. The regression correlations between the total fruit yield, fruit quality parameters, ion contents, and ECe or ETr could provide important information for salinity and irrigation water management with a compromise between the hot pepper yield and fruit quality.

Physiology of ‘Paluma’ guava under irrigation with saline water and nitrogen fertilization

The use of saline water in irrigation causes osmotic and toxic effects and nutritional imbalance in plants, leading to morphophysiological modifications in the leaves and compromising the production of photosynthetic pigments, which negatively reflects in the growth and development of the crops. Hence, this study aimed to evaluate the effect of irrigation water salinity on the content of photosynthetic pigments and leaf morphophysiology of guava seedlings cv. ‘Paluma’ under nitrogen (N) fertilization. A randomized block design was used, testing five levels of irrigation water electrical conductivity - ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1) and four N doses (541.1, 773.0, 1,004.9, and 1,236.8 mg of N dm-3 of soil) in a 5 x 4 factorial scheme with three replicates and five plants per plot. The contents of photosynthetic pigments in the leaves of the guava seedlings cv. ‘Paluma’ were inhibited by the increase in irrigation water salinity at 190 days after emergence, and the salt stress was lessened with the N dose of 1,004.9 mg dm-3 up to an ECw level of 1.2 dS m-1. Leaf morphophysiology of guava seedlings was not compromised by irrigation water salinity up to 1.5 dS m-1, and the highest values were obtained in plants fertilized with 541.1 mg of N dm-3.

Seed priming with cobalamin (vitamin B12) provides significant protection against salinity stress in the common bean

Salinity is an important environmental factor that has a negative impact on plant growth. Availability of growth regulators plays a crucial role to enhance adverse effects of salinity. The effects of saline water irrigation and cyanocobalamin (vitamin B12) priming were evaluated on some growth parameters and biochemical attributes of common bean (Phaseolus vulgaris L.). The seeds were primed in various concentrations of vitamin B12 (0, 11, and 22µM). Ten seeds of each group were sown in plastic pots. All pots were placed into a growth chamber. Four weeks after sowing, salt stress treatment was initiated and nine of the pots were subjected to salinity stress by NaCl solution (75mM) daily. The remaining plants, as controls were irrigated with tap water. Effects were determined by leaf area, root and shoot length, root and shoot dry matter, antioxidant enzyme activity, protein content, chlorophyll and carotenoids, lipid peroxidation and proline accumulation. The results demonstrated that application of vitamin B12 provided significant protection against salinity stress compared with non treated plants. According to the outcomes, antioxidant enzyme activity, lipid peroxidation, carotenoid and proline accumulation increased due to NaCl stress while protein, chlorophyll and carotenoids decreased. Seed priming with vitamin B12 induced these stimulatory effects on all the measured parameters. Root protein and leaf carotenoid content were not affected by vitamin treatment under conditions of salinity stress. These results suggest that, vitamin B12 may have a critical role as an effective antioxidant and regulates osmotic balance thereby enhancing bean plant's resistance to salinity.

Morfofisiologia de porta-enxerto de goiabeira irrigado com águas salinizadas sob doses de nitrogênio

The irrigation with saline water reduces crop growth and yield, resulting in the need of new techniques that enable the use of this natural resource in fruit growing. In this sense, the objective of this study was to evaluate the effect of saline irrigation water associated with different nitrogen doses on guava rootstock cv. Paluma morphophysiology. The experiment was carried out in a completely randomized blocks design, testing 5 electrical conductivity of irrigation water - ECw (0.3, 1.1, 1.9, 2.7 and 3.5 dS m-1) and four nitrogen doses for fertilization (541.1; 773.0; 1004.9 and 1236.8 mg dm-3), in a 5x4 factorial, with four repetitions. The increase in the ECw from 0.3 dS m-1 negatively affected the morphophysiology of guava rootstock cv. Paluma, especially during the younger phase of the crop. The N dose of 541 mg dm-3 stimulated the increase of most morphophysiological variables in guava rootstock during the period studied. The nitrogen fertilization did not reduced the salt stress effect on the evaluated variables.

Evaluating the effects of irrigation water salinity on water movement, crop yield and water use efficiency by means of a coupled hydrologic/crop growth model

Numerical simulation is an efficient approach for investigating the salt and water movement through soil profile and predicting of crop response to soil water deficit and salinity. In this study a coupled model that describes the soil water and solute transport by means of HYDRUS-1D model and crop growth process by means of growth module of EPIC was used. The model was calibrated and validated against field data, collected during two growing seasons in field plots of winter wheat irrigated with four levels of irrigation amount and water salinity of 5dsm−1 at the Fengqiu State Key Agro-Ecological Experimental Station, in North China Plain. The model was also used to evaluate the salinity stress on evapotranspiration (ET), grain yield and water use efficiency (WUE) and long-term use of saline water on grain yield and salt accumulation. Visual inspection and the obtained statistical parameters values showed that good agreement between measured and simulated data of soil water content, salt concentration, ET and grain yield. Evapotranspiration values of winter wheat were reduced under salinity stress conditions, mainly by reducing crop transpiration. The grain yields were reduced due to salinity stress, but the change trend of WUE was associated with precipitation amount. Increasing per saline water irrigation amount is an effective way to reduce the WUE decline rate under the low rainfall growing season as like that in simulation year. The average of ten years grain yield confirmed that a yield potential exceeding 86% could be maintained by saline water with 5dsm−1 when per irrigation volume more than 0.8 E, E denotes evaporation from an uncovered, 20cm diameter pan positioned 0–5cm above the crop canopy. There has a slight salt build-up after ten years simulation, and the quantity of salt accumulation decreased with the increase of irrigation volume. Thus, more attention should be paid to the sustainability of irrigated agriculture with low irrigation volume when using saline water irrigation. On the whole, field observations combined with the coupled model could be used to evaluate different agricultural managements on grain yield and soil salinity.

FEIJÃO-CAUPI IRRIGADO COM ÁGUA SALINA E ADUBADO COM ESTERCO BOVINO

O feijão-caupi constitui-se em um dos principais componentes da dieta alimentar nas regiões Norte e Nordeste do Brasil. Objetivou-se com este trabalho avaliar o desenvolvimento do feijão-caupi submetido à irrigação com água com diferentes níveis de salinidade e adubado com esterco bovino. O experimento foi conduzido em condições de ambiente protegido em casa de vegetação. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 2 x 5, referente ao solo com e sem aplicação de esterco bovino (20 ton ha-1), e cinco níveis de salinidade da água de irrigação (0,64; 1,32; 2,43; 3,22; 4,20 dS m-1), com quatro repetições. As variáveis avaliadas foram: altura da planta, diâmetro do caule, matéria seca da parte aérea, matéria seca das raízes, matéria seca total, número e comprimento de vagens, produtividade e a condutividade elétrica do solo. A altura da planta foi reduzida linearmente à medida que se aumentou a condutividade elétrica da água de irrigação (de 0,64 para 4,20 dS m-1), com uma redução de 24,07 e 32,34%, com e sem aplicação de esterco, respectivamente. A produtividade apresentou redução de 71,42% no tratamento que recebeu esterco e de 80,99% sem aplicação de esterco. Todas as variáveis analisadas foram influenciadas pela salinidade da água de irrigação promovendo redução do menor para o maior nível de salinidade. A aplicação de esterco bovino contribuiu para diminuir os efeitos da salinidade da água de irrigação.

Respons of wheat species to irrigation water salinity

This study was conducted to investigate the effects of different irrigation water salinity level on chromosomes and shoots of wheat with three different ploidy level (diploid, tetraploid and hexaploid). Greenhouse experiment revealed that irrigation water salinity level had significant effects on shoot dry weight, root dry weight, shoot length and root length (P&lt;0.05). The effects of ploidy level and cultivar shoot dry weight and root dry weight were also found to be significant (P&lt;0.05), but the effects on shoot length and root length were not significant (P&gt;0.05). Negative effects of salinity on shoot and root were started at 8 dS m-1. Also hexaploid wheat was more tolerant then tetraploid and diploid wheat to salinity. It was not determined that possible effects of irrigation water salinity to structure of chromosomes with current equipment and methods. Cell divisions were normal, but decreasing cell division rates were observed with increasing irrigation water salinity levels.

Fodder Yield and Quality of Pearl Millet (Pennisetum glaucum L.) Genotypes as Influenced by Salinity of Irrigation Water in North Western India

The present study was undertaken to assess the effect of irrigation water salinity and verieties on forage yield and quality of pearl millet in north western India. The experiment was conducted with four main-plot treatments consisting of levels of saline irrigation water i.e. normal (~0.6 dS/m) and 3, 6 and 9 dS/m irrigation water and two sub-plot treatments of pearl millet varieties i.e. AVKB-19 and ICMV-15111. The minimum DM content (15.71 and 16.68%), maximum CP content (9.26 and 7.48%) and (EE) (2.36 and 1.81%) was recorded at 1st cut and 2nd cut, respectively under good quality water. Among the genotypes, at 1st and 2nd cut, the maximum DM content (17.57 and 20.19%) was recorded in cv. ICMV-15111 compared to AVKB-19 (16.47 and 17.36%). In contrast, AVKB-19 recorded higher CP and EE level than ICMV-15111. Application of good quality water increased the DM yield by 23.34 and 13.69% and CP yield by 46.0 and 22.0% over irrigation water of EC 9.0 dS/m at 1st and 2nd cut, respectively. The cv. AVKB-19 gave higher DM (5.67 and 5.09 t/ha) and CP yield (1.42 and 1.25 q/ha) at the 1st and 2nd cut, respectively over ICMV-15111. The cv. AVKB-19 also recorded higher EE yield than ICMV-15111 at 1st cut while the reverse trend was observed at 2nd cut where ICMV-15111 which showed higher (P=0.05) EE yield over AVKB-19. The maximum NDF (66.35 and 70.64%) and ADF (36.50 and 39.89%) content was recorded with EC 9.0 dS/m at 1st and 2nd cut, respectively. The highest carbohydrate content was recorded with 9.0 dS/m EC water irrigation for 1st and 2nd cuts. Therefore, ABKV-19 genotype of pearl millet proved to be superior and might be adapted for getting higher fodder yield with better quality as compare to the ICMV 15111 under saline environment in north-western region of India.