English abstract
Sultanate is categorized as arid country with low rainfall and high evapo transpiration (ET). Ground water is the main source of water for both domestic and agriculture use. High water demand has led to over pumping and prolonged lack of rains has reduced the extent of recharge. This situation has progressively deteriorated the quality of both water and soil towards salinity. The affected areas are mostly the farms near the coast, which have abundant but saline water. Hence, the use of salir water cannot be avoided. Therefore, it is needed that such management practices be devised which ensure sustainable use of saline water with minimum loss to crop yields and least threat to soil health.
This experiment was conducted during summer 2007 at Agricultural Research Center, Directorate General of Agricultural & Livestock Research in Rumais to evolve some practicable and economical management practices, which can mitigate the potential deleterious effects of saline waters to plants and soil. A split block design was applied with 3 factors (Irrigation rates, water salinity and mulch) and 3 replicates. Two categories of irrigation water (EC 3 & 6 d S/m), three level of irrigation quantities (100%, 120% & 140% of ETC), two management practices (Plastic sheet and crop residues mulch=date palm leaves) vs. control, and their interaction on soil EC, plant parameters and yield were investigated. Sorghum forage crop was grown. Moisture percentage and soil temperature underneath different mulches were monitored throughout the experiment.
The results revealed that increasing amounts of irrigation water from 100% to 120% and 140% of ETC increased yields by 20 and 25% (from 47 to 57, and 59 ton/ha) respectively, Data of the experiment indicated that 6 ds/m decreased green forage yield (52 t/ha) compared with 3 dS/m (56.5 t/ha) but also increased soil EC significantly. However, the plastic sheet and crop residue mulch proved greatly helpful to control the bad effects of saline water on crop yield and soil EC. The positive effects of both the treatments were found to be significant over control (No management practice). Date palm leaf mulch proved superior in crop yield. The recorded green yields for date palm mulch, plastic mulch and control were: 58.7, 52.7 and 51.9 tha respectively that were assessed as significant statistically. Both type of mulches proved successful in controlling increase in soil EC and keeping it as 2.7dS/m as against 3.6 dS/m for control. Another benefit of date palm mulch was observed in keeping the soil cool when compared with control as well as plastic mulch. The recorded respective mean temperatures were; 33.2, 34.0 and 35.4. Date palm mulch also proved useful in conserving the moisture and means determined values were 16.5, 14.9 and 14.8 % for date palm mulch, plastic mulch and control respectively.
The effect of Gonu cyclone was also studied. No permanent effect on soil moisture and temperature was recorded but soil EC decreased considerably. Plant parameters remained un-affected with cyclone event.
