Use of sea water for wheat irrigation [electronic resource]: 2-effect on soil chemical properties, actual evapotranspiration and water use efficiency.

Includes reference.

A greenhouse pot experiment was conducted to evaluate the influence of water management using diluted sea water and organic manure application on salinity build up in a calcareous soil (Typic Calciorthents) from the area west of the Nile Delta, Southern Tahreer, EI-Beheira Governorate, cultivated with wheat plant (Triticum aesitivum L. V. Sakha 92). The modes of saline water application included irrigation with water having 6720 mgl-1 (1:5 diluted sea water), 8768 mgl-1 (1:3 diluted sea water) and a tap water as a control having 256 mgl-1. Chicken manure application was done as a soil amendment (1.5% w/w), while water management practices were done as the following irrigation frequencies, namely, (a) irrigation with diluted sea water along the growth period, (b) irrigation with diluted sea water until pre-flowering stage then with tap water and (c) irrigation with saline water for three times and once with tap water along the growth season. Certain chemical properties of the studied soil were evaluated during different growth periods and after harvesting of wheat plant. Actual evapotranspiration (ETa) ratio and water use efficiency (WUE) were calculated. The obtained results indicated that increasing water salinity increased soluble cations and anions with different rates. For instance, SO4-- concentration in soil extract showed considerable increases as the time increases, reaching 6 folds of those found for the soils irrigated with tap water. Also, SAR increases to about 288, 325 and 57% for the vegetative, yield formation and harvesting stages, respectively. On the other hand, increasing salinity level of irrigation water decreased the actual evapotranspiration (ETa) and water use efficiency (WUE) values of wheat plant as compared to plants irrigated with tap water. Regarding the effect of irrigation frequencies on soil salinity, the lowest values of EC and SAR as well as soluble ions were associated with (c) frequency while the highest ones were associated with (a) frequency. In addition, irrigation frequency (c) gave the highest values of Eta and WUE as compared to the other two irrigation frequencies request alternation of saline and fresh water at a sequence of 3 to 1 caused considerable attenuation of salinity build-up as indicated by increasing its levels in the soil. Such increases reached about 5 folds comparing to those irrigated with tap water. Chicken manure application increased soil EC values as well as ETa and WUE, but lowered SAR values. It can be concluded that addition of organic manure and water management as (c) water irrigation frequency had promotive effect on reducing the salt stress in the plant root zone and providing the growing plants with adequate amounts of water and available nutrients as with as avoiding loss caused by extended periods of water stress under saline conditions. Key words: Diluted sea water, Calcareous soil, Chicken manure, and irrigation frequencies, EC, SAR, ETa and WUE.

Summary in Arabic.

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