Utilization of Soil Mulching Practices to Improve Drought Management in Arid Region

The main objective of this study was to evaluate the effect of deficit irrigation and mulching practices on yield and water use efficiency of corn, some soil physical properties. The experiment was conducted in Soil and Water Resource Research Station at Baghdad 33o.14 ( North) and 44o.4 ( East). Randomized Complete Block Design  ( RCBD ) with three replicates was used. Corn was cultivated in fall season 2015 under four treatment were investigated, Full irrigation ( I1 ) and deficit irrigation (reduction 30% from irrigation requirement) ( I2 ) without mulching application ( M0 ) and with mulching application ( M1 ).Amounts and timing of applied irrigation water were estimated based on  measurement of soil water content by using soil moisture sensor type  Diviner-2000. Applied irrigation water measured at each irrigation for the whole growing season .Actual evapotranspiration ( ETa) was estimated by measuring the volumetric soil water content at each irrigation and before the next irrigation. (Actual water requirement, water use efficiency , grain yield, Hydraulic conductivity, Percent of soil stable aggregates, soil organic carbon, Bulk density) were estimated. The  results showed that: were : (i) Deficit irrigation (reduction 30% from irrigation requirement)  (I2) caused decreasing in irrigation water amount with 1600 m3. ha-1season-1  ( 26 % ) as compared with full irrigation  (I1) ( 6200 m3. ha-1season-1) and does not cause moral shortage in grain yield about 14 %. (ii) Full irrigation  ( I1 ) caused increasing in grain yield with  14.1 %  compared  with deficit irrigation  ( I2 ). (iii) Mulching application ( M1 ) caused increasing in grain yield and water use efficiency with  22.5%  and 21.8 % ,respectively, compared without mulching application ( M0 ). (iv) The mean maximum value grain yield with 7710 kg ha-1 were observed in treatment combination I1 M1 and minimum value 5420 kg ha-1  were observed in treatment combination I2M0.  (v) Full irrigation ( I2 ) caused increasing in hydraulic conductivity , Percent of soil stable aggregates and soil organic carbon with 24.1% , 19.4 % and 9.5 % , respectively compared  deficit irrigation (reduction 30% from irrigation requirement)      ( I2 ).( vi ) Mulching application ( M1 ) caused increasing in hydraulic conductivity , Percent of soil stable aggregates and soil organic carbon with 61.5 , 57.1 and 30.3 % respectively, compared without mulching application (M0 ).On the other hand ( vii ) Mulching application ( M1 ) caused decreasing in Bulk density with 7.8 % compared without mulching application ( M0 ). (viii) The mean maximum value saturated hydraulic conductivity, soil percent of stable aggregate and soil organic carbon with 27.6 mm hr-1, 28.7% and 2.75 g kg-1 respectively were observed in treatment combination I1M1 and minimum value  13.2 mm hr-1, 14.9%  and 1.91 g kg-1  respectively, were observed in treatment combination I2M0. (viiii) Maximum value of soil bulk density 1.42 µg m-3 was observed in case of treatment combination I2M0 and minimum value of soil bulk density 1.27 µg m-3 was observed in case of  I1M1 combination