宽垄沟播种植模式对夏玉米生长发育及水分利用率的影响

探讨水地条件下种植模式对夏玉米产量及水分利用的影响,为夏玉米节水种植高产稳产栽培提供依据。以玉米品种"登海685"为试验材料,研究宽垄沟播和等行距平播模式下不同种植密度(6.00,6.75,7.50万株/hm~2)对夏玉米生长发育、产量、养分吸收及水分利用率的影响。结果表明:沟播种植模式较平播增加玉米植株株高,使茎粗和单株干物质重降低。沟播模式的穗性状比平播处理较优,单穗重增加,且受种植密度影响较小,表现出明显的边行优势。沟播模式的玉米叶片叶绿素相对含量始终高于平播处理,生育期延长,为后期籽粒形成提供了物质保障。在种植密度为7.50万株/hm~2时,沟播模式夏玉米产量最高。沟播模式下夏玉米灌水量较平播减少52.9%,灌水时间减少50.1%,日均蒸发量减少,且水分含量高于平播处理,使灌溉水利用效率提高139.5%,水分利用效率平均提高16.7%。可见,宽垄沟播是夏玉米增产增效的一种节水种植模式,明显提高玉米水分利用效率。     

Effect of saline irrigation water composition on selenium accumulation by wheat

Abstract

Trace amounts of selenium (Se) are essential for animal and human nutrition. However, the optimum concentration range is very narrow and outside of this range deficiencies or toxicities can occur. Potentially harmful levels of Se in soils and irrigation waters have been reported in regions where salinity is also a hazard. This study was conducted to determine the effects of irrigation water composition and salinity level on Se accumulation in leaves and grain of spring wheat (Triticum aestivum L. cv. ‘Yecora Rojo'). Plants were grown in greenhouse sand cultures and irrigated with complete nutrient solution. Salinity treatments were initiated 4 days after planting by irrigating the seedlings with either chloride‐dominated waters or with waters containing both chloride and sulfate salts. Compositions of the mixed salt waters were designed to simulate saline drainage waters commonly present in the San Joaquin Valley of California. The experimental design was a randomized complete block with two salinity types (Cl^? or mixed salts), eight salinity levels (osmotic potentials=0.07, 0.16, 0.21,0.30.0.36, 0.44, 0.52, and 0.63 MPa), and three replications. Four weeks after planting, Se (1 mg L^?1 as sodium selenate) was added to all irrigation waters. In the chloride system, the molar ratio of SO₄ ^2‐:SeO₄ ^2‐ was approximately 110 across all salinity levels, whereas in the mixed salt system, the SO₄ ^2‐ SeO₄ ^2‐ratio in solution increased from about 300 to 4,700 as salinity increased. Selenium concentration was determined in fully‐expanded flag leaf blades and grain. Salinity type, and to a lesser extent, salinity affected Se accumulation. In the Cl‐system, wheat accumulated Se to levels that may be potentially harmful to livestock and humans, e.g., blade‐Se ranged from 435 to 295 mg kg^?1 dry wt; grain‐Se ranged from 81 to 54 mg kg^?1 dry wt. Under the saline conditions of the mixed salt system, the inhibition of selenium uptake by sulfate reduced both blade‐ and grain‐Se to levels that would minimize the health risk to consumers.     

SOYBEAN RESPONSE AND ION ACCUMULATION UNDER SPRINKLER IRRIGATION WITH SODIUM-RICH SALINE WATER

The magnitude of crop growth and yield depends on the salinity level, the toxic ions present, and the irrigation system used. In order to study the effect of saline sprinkler irrigation on soybean growth and ionic accumulation in plant tissues a pot experiment was set up. There were three irrigation water quality treatments [electrical conductivity (EC) 0, 2, and 4 dS m^?1]. Soybean aerial biomass was 25% lower than the Control when irrigation salinity was 4 dS m^?1. Clearly salinity entering via leaves affected the grain filling stage and severely reduced soybean grain production (80% reduction) when salinity in irrigation water surpassed 2 dS m^?1. Sprinkler irrigation aggravates soybean's low salinity tolerance and restricts its cropping in such conditions. For early stages two linear relationships between leaf chloride (Cl^?) concentration (Y = 14.2–2x) or potassium (K⁺)/ sodium (Na⁺) ratio (Y = 5.3x?3.4) and soybean grain yield were found. Both relationships may be used as diagnostic tools for soybean growing under saline sprinkler irrigation.     

Manure and nitrogen fertilizer effects on corn productivity and soil fertility under drip and furrow irrigation

A field experiment was conducted at the Arkansas Valley Research Center in 2005 through 2007 to study the effects of manure and nitrogen fertilizer on corn yield, nutrient uptake, N and P soil tests, and soil salinity under furrow and drip irrigation. Manure or inorganic N was applied in 2005 and 2006 only. There were no significant differences in corn yield between drip and furrow irrigation even though, on average, 42% less water was applied with drip irrigation. Inorganic N or manure application generally increased grain yield, kernel weight, grain and stover N uptake, and grain P uptake. Nitrogen rates above 67 kg ha^?1 did not increase grain yield significantly in 2005 or 2006, nor did manure rates in excess of 22 Mg ha^?1. High manure rates increased soil salinity early in the season, depressing corn yields in 2005 and 2006, particularly with drip irrigation. Salts tended to accumulate in the lower half of the root zone under drip irrigation. Residual nitrate nitrogen from manure and inorganic N application sustained corn yields above 12.0 Mg ha^?1 in 2007. More research is needed to develop best manure and drip irrigation management for corn production in the Arkansas Valley.     

基于加权灰色关联模型优选夏玉米沟灌方式

该文建立加权灰色关联综合评价模型,基于夏玉米耗水量、产量及其构成因素（穗长、穗周长、穗粒数、穗行数、百粒质量和产量）对沟灌方式进行优选。结果表明,同一水分控制下限,无论是产量综合评价,还是耗水及水分利用效率综合评价,宽垄沟灌种植模式的灰色关联综合评价均优于常规沟灌种植模式;其中灌水控制下限为田间持水量的70%（field water holding capacity, FC）的宽垄沟灌种植处理在第2层综合评价中耗水评价虽然位次第3,但产量评价和水分利用效率评价位次第1,在第1层综合评价中灰色关联度最大（0.852）,故灌水控制下限为70%（70%FC）最佳;其次为灌水控制下限为60%（60%FC）的宽垄沟灌种植处理,关联度为0.788,60%FC与70%FC二者关联度相差较小。加权灰色关联综合评价模型的评判结果与大田试验结果相吻合。因此,最终方案的最终选定可根据当地水资源状况而定,对于水资源相对丰富地区建议采用W70灌水方式,对于水资源相对匮乏地区建议采用W60灌水方式。研究可为灰色关联度方法在节水灌溉研究中的应用提供参考。     

Effect of salt stress on photosynthesis and related physiological characteristics of Lycium ruthenicum Murr

Halophytes could withstand the hyper-salinity soil and survive widely in areas where soil salt content is high because they can endure salt stress to a certain extent. Lycium ruthenicum Murr (LRM), with significant nutritional and medicinal values, is one of the most important native halophytes in the arid oasis-desert transition zone of northwestern China. In recent years, artificially planting LRM has been being popular since it can improve saline-alkalized soil and increase the income of local farmers as well. More efforts about the artificial planting of LRM are put in enhancing the productivity and quality, but survivorship of LRM seedling by appropriate saline irrigation is still unclear in arid areas. A field experiment was conducted to explore the responses of LRM to four levels of saline water irrigation (Ec of irrigation water: 2.00?μs?cm^?1 (T₁), 4.51?μs?cm^?1 (T₂), 6.89?μs?cm^?1 (T₃), and 9.00?μs?cm^?1 (T₄)) during the growing seasons in 2014 and 2015. The average soil electrical conductivity (Ec_a) in 0–60 cm depth increased while the biomass of LRM decreased with increasing Ec of irrigation water, and the differences of Ec_a among treatments decreased with increasing salinity level. In contrast to previous research findings, salt stress had more significant effect on photosynthesis and chlorophyll fluorescence of LRM, in which great changes were caused by a threshold following the increased salinity. Most of the light energy absorbed by LRM was used for photosynthesis and heat dissipation when soil salinity was low, what was used for chlorophyll fluorescence when soil salinity was high. The results of the experiment indicate that T₂ was the most suitable irrigation method for artificially planting LRM in the field, and it’s the key to save freshwater resources in arid areas and improve the production of saline-alkali land.     

Wheat response to interactive effects of boron and salinity

Abstract

In semiarid regions with irrigated agriculture, excess boron (B) often occurs in association with moderate to high salinity. However, little information is available on plant uptake of B under saline conditions. This greenhouse study was conducted to determine the interactive effects of salinity and varying concentrations of boron on growth, yield and ion relations of wheat (Triticum aestivum L., cv. ‘Yecora Rojo'). Plants were grown in sand cultures that were irrigated four times daily with modified Hoagland's nutrient solution. Sixteen treatments were initiated 4 d after planting in a completely randomized factorial experiment with 4 salinity levels (electrical conductivities of the irrigation waters=1.5, 4, 8, and 12 dS m^?1) and 4 B concentrations (1, 5, 10, and 15 mg L^?1). Salinizing salts were NaCl and CaCl₂ (2:1 molar basis). Symptoms of B toxicity were closely correlated with B concentration in the leaves and injury became severe when leaf‐B exceeded 400 mg kg^?1. At each concentration of external B, shoot‐B was least under nonsaline conditions and increased significantly as salinity increased. Shoot‐calcium (Ca) concentration increased with increasing salinity, but was unaffected by applied B. Shoot‐magnesium (Mg), and potassium (‐K) decreased significantly in response to increases in salinity and substrate B. Salinity and B as well as their combined effects significantly reduced wheat biomass production, yield components, and final grain yield.     

Effect of soil water management and different sowing dates on maize yield and water use efficiency under drip irrigation system

A 2-year field experiment (2012–2013) was conducted to evaluate the yield and water use efficiency (WUE) response of maize (Zea mays L.) to different soil water managements at different sowing dates. The experiment included three sowing dates (22 June, 6 July and 21 July) and four irrigation regimes based on maximum allowable depletion (MAD) of the total available soil water (TAW). The irrigation treatments were marked by I₁ to I₃ as 40%, 60% and 80% MAD of TAW, respectively, and with no irrigation. The results showed that grain yield reduced when planting was delayed in both years, ranging from 6105 to 4577 kg ha^?1 in 2012 and from 7079 to 5380 kg ha^?1 in 2013. However, WUE increased when planting was delayed from 22 June until 21 July. Also the highest grain yield was observed in the first irrigation treatment (MAD = 40%) in both years, and the highest WUE was obtained in the second irrigation treatment (MAD = 60%) with 1.64 and 1.61 (kg m^?3) in 2012 and 2013, respectively. These findings suggest that delay in planting date and the use of MAD = 60% treatment in Mediterranean-type region such as Golestan, Iran, can be useful in saving water that is highly important in such regions.     

Salinity and drought affect yield response of bell pepper similarly

Abstract

There is a growing realization that an increasing number of countries are approaching full utilization of their conventional water resources and that the quantity of good-quality water supplies available to agriculture is diminishing. Effects of irrigation regime and irrigation water salinity on bell pepper including yield, fruit number and quality, vegetative and root growth, evapotranspiration and water use efficiency were investigated in this study by conducting two different experiments. Six different salinity levels of irrigation water and four different irrigation regimes were used as treatments. Considering the results from irrigation water salinity experiment, it can be concluded that as soil salinity increases, water consumption, water use efficiency, yield and other vegetative growth parameters of bell pepper were decreased. A polynomial relationship between soil salinity and water consumption was observed. It was found that bell pepper is moderately sensitive to salinity with a 1.2 dS m^?1 threshold and a 10.9% slope value. In the irrigation regime experiment, limited irrigation caused decreases in water consumption, yield and vegetative growth of bell pepper. Yield response factors were close in the cases of irrigation regime (1.50) and irrigation water salinity (1.40). Total soluble solids of bell pepper were increased due to both irrigation water salinity and water application rate but not dry matter ratio. Considerable water consumption decreases because of salinity were determined. Therefore, the effect of irrigation water salinity should be considered in irrigation management to prevent excess saline water application and to protect the environment.     

Effects of Irrigation Water Salinity and Leaching Fraction on Yield and Evapotranspiration in Spring Wheat

To determine the effects of irrigation water salinity and leaching fraction on crop evapotranspiration (ETc), grain yield, straw yield, shoot sodium (Na), and chloride (Cl) concentrations of spring wheat (Triticum aestivum L.) cultivar ‘Onfarom 9,’ a pot experiment was conducted using saline soil with electrical conductivity of soil paste extract (ECe) of 13.2 dS m^?1. A factorial experiment with a completely randomized design replicated seven times was used with three levels of saline irrigation water (4, 9, and 12 dS m^?1) and four leaching levels (0, 17, 29, and 37%) included as the factors. The results showed that ETc significantly decreased as a result of an increase in irrigation water salinity (ECi) and decrease in leaching level. Crop evapotranspiration deficit and decreasing irrigation and drainage water effectively resulted in grain and straw yield reduction. Increase in ECi increased accumulation of Cl and Na in crop shoot, but application of leaching decreased this accumulation.     

Sodicity Intensifies the Effect of Salinity on Grain Yield and Yield Components of Wheat

ABSTRACT

This study reports the relationship of the leaf ionic composition with the grain yield and yield components of wheat in response to salinity x sodicity and salinity alone. The study was conducted in soil culture in pots with three treatments including control (ECe 2.6 dS m^{? 1} and SAR 4.53), salinity (ECe 15 dS m^{? 1} and SAR 9.56), and salinity x sodicity (ECe 15 dS m^{? 1} and SAR 35). The soil was treated before being put in the pots and the pots were arranged in a completely randomized factorial arrangement with five replications. The seeds of three wheat genotypes were sown directly in the pots and the study was continued till the crop maturity. At booting stage, the leaf second to the flag leaf of each plant was collected and analyzed for sodium (Na⁺), potassium (K⁺), and chloride (Cl^?). At maturity, plants were harvested and data regarding grain yield and yield components were recorded. This study shows that salinity and sodicity in combination decreases the grain yield of wheat more than the salinity alone with a greater difference in the sensitive genotype. This study also shows that as for salinity, the maintenance of lower Na⁺ and higher K⁺ concentrations and higher K⁺: Na⁺ ratio in the leaves relates positively with the better development of different yield components and higher grain yield in saline sodic soil conditions. Although, the leaf Cl^? concentration was increased significantly by salinity as well as salinity x sodicity and would have affected the growth and yield, yet it does not seem to determine the genotypic tolerance or sensitivity to either salinity or salinity x sodicity.     

Enhancing maize grain yield under salt-affected field conditions using salt-resistant maize hybrids and higher planting density

Background

In arid and semiarid countries, grain yield of maize is increasingly impaired by soil salinity. Beside soil amelioration, the development of salt-resistant cultivars is a possibility to enhance crop yield on salt-affected soils.

Aims

This study aimed at testing yield performance in the field of salt-resistant maize hybrids on a salt-affected soil. In addition, planting density was optimized under the saline conditions.

Methods

Four salt-resistant maize hybrids (Zea mays L. SR-05, SR-12, SR-15, and SR-16) were grown under control (EC = 2.0–2.5 dS m⁻¹) and saline (EC = 10.0–12.0 dS m⁻¹) field conditions and compared to the salt-sensitive maize cv. Pioneer-3906. Planting density (5, 8, or 11 plants m⁻²) was optimized for saline soil conditions for SR-12 and the local hybrid EV-78.

Results

Yield of Pioneer-3906 was significantly reduced under salinity because of inhibited kernel setting, whereas the SR hybrids showed no decrease in grain yield. Based on grain yield, the optimum planting density was 8 plants m⁻² with no further increase with 11 plants m⁻². In contrast to SR-12, for cv. EV-78 no increase of harvest index with 8 relative to 5 plants m⁻² was observed.

Conclusions

Vegetative growth of Pioneer-3906 and the SR hybrids was decreased due to Phase-I effects but neither due to water deficiency nor ion toxicity. The experiment corroborated the salt resistance of the SR hybrids under field conditions. Under saline conditions, optimum planting density of salt-resistant cultivars may be higher than under nonsaline conditions when sufficient water supply by artificial irrigation is guaranteed.     

Maize (Zea mays L.) Grain Yield Response to Methods of Nitrogen Fertilization

ABSTRACT

In the developing world, fertilizer application is commonly achieved by broadcasting nutrients to the soil surface without incorporation. A commonly used nitrogen (N) source is urea and if not incorporated, can sustain N losses via ammonia volatilization and lower crop yields. This study evaluated the effect of planting, N rate and application methods on maize (Zea mays L.) grain yield. An experiment with a randomized complete block design (nine treatments and three replications) was established in 2013 and 2018 in Oklahoma. The planting methods included; farmer practice (FP), Oklahoma State University hand planter (OSU-HP), and John Deere (JD) mechanical planter. Side-dress N application methods included; dribble surface band (DSB), broadcast (BR), and OSU-HP. Nitrogen was applied at the rate of 30 and 60 kg ha^?1 as urea and UAN at V8 growth stage. On average, planting and applying N at 60 kg ha^?1 using OSU-HP resulted in the highest yield (11.4 Mg ha^?1). This exceeded check plot yield (5.59 Mg ha^?1) by 104%. Nitrogen application improved grain yield by over 57% when compared to the 0-N check (8.77 Mg ha^?1). Mid-season N placement below the soil surface using OSU-HP makes it a suitable alternative to improve grain yield.     

Soil Erosion as A ffected by Polyacrylamide Application Under Simulated Furrow Irrigation with Saline Water

The reduction of soil and water losses under furrow irrigation with saline water is important to environmental protection and agricultural production.The objective of this study was to determine the effect of polyacrylamide(PAM)application on soil infiltration and erosion under simulated furrow irrigation with saline water.Polyacrylamide was applied by dissolving it in irrigation water at the rates of 1.5,7.5,and 15.0 mg L^-1 or spreading it as a powder on soil surface at the rates of 0.3,1.5,3.0,and 6.0 g m^-2,respectively.The effectrolyte concentration of tested irrigation water was 10 and 30 mmolc L^-1 and its sodium adsorption ratio(SAR)was 0.5,10.0,and 20.0(mmol_c L^-1)_0.5.Distilled water was used as a control for irrigation water quality.Results indicated that the effectrolyte concentration and SAR generally did not significantly affect soil and water losses after PAM application.Infiltration rate and total infiltration volume decreased with the increase of PAM application rate.Polyacrylamide application in both methods significantly reduced soil erosion,but PAM application rate did not significantly affect it.The solution PAM application was more effective in controlling soil erosion than the powdered PAM application,but the former exerted a greater adverse influence on soil infiltration than the latter.Under the same total amounts,the powdered PAM application resulted in a 38.2%-139.6% greater infiltration volume but a soil mass loss of 1.3-3.4 times greater than the solution PAM application.     

TREATED EFFLUENT AND SALINE WATER IRRIGATION INFLUENCES SOIL PROPERTIES,YIELD, WATER PRODUCTIVITY AND SODIUM CONTENT OF SNOW PEAS AND CELERY

To determine the effects of irrigation water quality, plants were irrigated with normal potable water [0.25 dS m^?1 electrical conductivity (EC), 25 mg L^?1 sodium (Na), 55 mg L^?1 chloride (Cl)], treated effluent (0.94 dS m^?1 EC, 122 mg L^?1 Na, 143 mg L^?1 Cl) and saline water with low salinity (1.24 dS m^?1 EC, 144 mg L^?1 Na and 358 mg L^?1 Cl) and high salinity (2.19 dS m^?1 EC, 264 mg L ^?1Na and 662 mg L^?1 Cl) for snow peas, and high salinity (3.07 dS m^?1 EC, 383 mg L^?1 Na and 965 mg L^?1 Cl) and very high salinity (5.83 dS m^?1 EC, 741 mg L^?1 Na and 1876 mg L^?1 Cl) for celery. The greater salts build up in the soil and ion toxicity (Cl and Na) with saline water irrigation contributed to significantly greater reduction in root and shoot biomass, water use, yield and water productivity (yield kg kL^?1 of water used) of snow peas and celery compared with treated effluent and potable water irrigation. There was 8%, 56% and 74% reduction in celery yield respectively with treated effluent, high salinity and very high salinity saline water irrigation compared with potable water irrigation. The Na concentration in snow peas shoots increased by 54%, 234% and 501% with treated effluent, low and high salinity saline water irrigation. Similarly, the increases in Na concentration in celery shoots were 19%, 35% and 82%. The treated effluent irrigation also resulted in a significant increase in soil EC, nitrogen (N) and phosphorus (P) content compared with potable water irrigation. The heavy metals besides salts build up appears to have contributed to yield reductions with treated effluent irrigation. The study reveals strong implications for the use of saline water and treated effluent for irrigation of snow peas and celery. The salt build up within the root zone and soil environment would be critical in the long-run with the use of saline water and treated effluent for irrigation of crops. To minimize the salinity level in rhizosphere, an alternate irrigation of potable water with treated effluent or low salinity level water may be better option.     

The Effect of Moderate Salinity on Nitrate Leaching from Bermudagrass Turf: A Lysimeter Study

A column lysimeter study was conducted under greenhouse conditions to determine the impact of moderately saline irrigation water on NO₃ leaching from turfgrass. Bermudagrass (Cynodon dactylon L. ‘NuMex Sahara’) was fertilized at three N levels (25, 50 and 75 kg NH₄NO₃-N ha^?1 month^?1) and irrigated with saline water (0, 3.0 and 6.0 dS m^?1) in a factorial arrangement. Leachate was analyzed for salinity and NO₃, and clippings were collected and analyzed for total N. Nitrate leaching was not affected by either N level or salinity. Nitrate concentrations in the leachate were low, averaging approximately 0.3 mg N L^?1; less than 1% of the applied N leached. Longer-term N allocation to leaf growth accounted for up to 98% of applied N, whereas short-term allocation, determined using ¹⁵N, ranged from 46–67%. Salinity had no affect on clipping yield, the biomass of root and verdure, or root distribution. These data indicate the potential for moderately saline irrigation water to be used on bermudagrass turf without increasing NO₃ contamination of groundwater, as long as leaching is adequate to prevent rootzone salinity reaching damaging levels.     

Impacts of different water salinity levels on salt tolerance,water use,yield, and growth of chives (Allium schoenoprasum)

ABSTRACT

Using saline irrigation water for crop production continues to gain more importance year by year, especially in regions where freshwater resources are very scarce. Therefore, this study was carried out to investigate the effects of six water salinity levels (0.38 (control), 1.0, 2.0, 4.0, 6.0, and 8.0 dSm^?1) on salt tolerance, evapotranspiration, and yield of chives under a rain shelter. The experiment was laid out in pots using a randomized plot design with four replicates of each treatment. Leaf fresh-dry weights, plant height, evapotranspiration, and water use efficiencies of chive plants were significantly affected by increasing levels of salinity. The results revealed that chives can be classified as a salt-sensitive crop with a threshold value of 1.13 dSm^?1 and relative yield decreased by 6.19% per unit increase of soil salinity. In conclusion, with appropriate leaching management practices, irrigation water with 0.38 dSm^?1 salinity level is recommended for chives production.     

The Productivity of Subsequent Wheat Enhanced with Residual Carbon Sources and Phosphorus under Improved Irrigation System

ABSTRACT

A two-year consecutive experiment was conducted at agriculture Research Institute Mingora Swat, Pakistan during Rabi 2016–17 and 2017–18 to study the residual effect of carbon sources on water use efficiency and subsequent wheat productivity. Carbon sources (peach leaf and rotten fruits on dry basis, compost of peach residues and biochar of these residues), Three P rates (P1 = 50, P2 = 75, and P3 = 100 kg P ha^?1) with two irrigation levels (225 and 175 mm) along with traditional planting with no irrigation, were used in the experiment. No carbon sources or phosphorus was applied to the wheat crop at any stage. The results clearly indicated that CS such as biochar with improved irrigation system of 225 mm could enhance the soil water availability in 0–100 cm during the key growth stages, as well as WUE and rainfall use efficiency were improved by 34% and 51% as compared with no irrigation, respectively. Maximum yield components were produced by compost while biological yield was increased with biochar amendments. It is concluded that irrigation volume of 225 mm produced higher grain yield when wheat was sown after the preceding crop treated with biochar and 75 kg P ha^?1. It is concluded that biochar with 225 mm irrigation level is a suitable treatment for efficient consumption of local rainfall and increase subsequent wheat productivity under the northern climatic scenario of Pakistan because it improves the Evapo Transpiration (WUE), Radiation Use Efficiency (RUE) and reduces ET levels, thereby enhancing the grain yield, net pro?t, and food security.     

种植方式和灌溉定额对碱化盐土及紫穗槐生长的影响

针对甘肃白银碱化盐土表层土壤盐分高、植物生长困难的生产问题,在统一施用脱硫石膏18t/hm^2的基础上,通过2 a田间试验,在起垄沟植和未起垄种植2种种植方式下设置3个灌溉定额:8 250、9 750和11 250 m^3/hm^2,研究不同种植方式及灌溉定额对土壤pH值、碱化度、含盐量及紫穗槐生长的影响。试验结果表明:1)各处理均显著降低了土壤pH值、碱化度和含盐量;起垄沟植方式下垄沟内可汇集灌溉水和降水,提高土壤含水率;在0~40 cm土层起垄处理的土壤盐分比未起垄处理低15.7%,起垄沟植处理可以形成"高水低盐"的水盐环境,从而使紫穗槐的成活率、株高、冠幅均高于未起垄处理;2)2种种植方式下,随灌水量增加脱盐效果越显著,紫穗槐的成活率、株高、冠幅指标随灌水量增加而增加;灌溉定额为9 750和11 250 m^3/hm^2时,紫穗槐生长指标无显著差异。考虑到研究区地处干旱区,水资源有限,灌水量过多不仅浪费水资源还会增加发生次生盐渍化的风险,因此,施用脱硫石膏并起垄沟植适宜于甘肃白银碱化盐土紫穗槐种植,且适宜灌溉定额为9 750 m^3/hm^2。     

Drip irrigation and nitrogen fertilization alter phenological development and yield of spring maize (Zea mays L.) under semi-arid conditions

Abstract

Maize response to deficit water and nitrogen for assessing phenological development and yield was studied under semi-arid conditions. Experiment consisting three drip irrigation levels, replenish 60 (DI₆₀), 80 (DI₈₀) and 100 percent (DI₁₀₀) of cumulative pan evaporation, and four nitrogen doses 50 (RN₅₀), 75 (RN₇₅), 100 (RN₁₀₀) and 125 (RN₁₂₅) per cent of recommended nitrogen. A Furrow irrigated treatment was kept as control/check. Significant earliness in visibility of collar of 8^th leaf, tasseling, silking and significant delay in dough stage and physiological maturity was recorded under well water treatment DI₁₀₀ as compared to DI₆₀. Days to collar of 8^th leaf, tasseling and silking had significant negative correlation, and duration of yield formation phase and days to physiological maturity had significant positive correlation with grain yield. Higher DM production, longer yield formation phase and late physiological maturity led to significantly higher grain yield under DI₁₀₀. In case of nitrogen levels, phonological characteristics like collar of 8^th leaf, tasseling and silking were significantly delayed, and dough stage and physiological maturity were advanced under nitrogen deficit treatment RN₅₀ as compared to RN₁₀₀ and RN₁₂₅. Significantly higher dry matter production and longer yield formation phase observed led to significant higher SCY under RN₁₀₀ and RN₁₂₅ as compared to RN₅₀. Yield formation phase was significantly longer under drip irrigated crop as compared to control during 2^nd year of study. Crop phenological development significantly affected by drip irrigation regimes and nitrogen levels, and there was significant correlation between phenological stages development and grain yield.