Residual effect of applying plant waste composts on calcareous soils under different irrigation systems

A field experiment was carried out at Maryut Experimental Station of the Desert Research Center, in summer 2006, to evaluate the effects of residual application of plant waste composts on physical and chemical properties of calcareous soil, as will as the yield of corn plants growing under different irrigation systems. The experiment was carried out in split plots design, where irrigation systems occupied the main plots, and the compost treatments occupied the sub main plots. The used irrigation systems were: Traditional short furrows (TF), Gated-pipe long furrows (GF), Surface drip (D); and Subsurface drip at 20-cm depth (SD). The compost treatments were: 0, 10, 20, and 30-m3 compost /fed. denoted as (C0);(C1); (C2); and (C3), respectively. The obtained results indicated that both irrigation systems and compost amounts had significant influences on yield and some physicalchemical properties of soil. The average values of losses water ranged from 31.6 to 37.3 %, 27.0 to 29.9%, 13.8 to 16.0% and 8.9 to 15.4% by (TF), (GF), (D) and (SD) treatments, respectively with recent addition of compost. While average values of water distribution uniformity (DU) under (TF), (GF), (D) and (SD) treatments ranged from 0.54 to 0.59, 0.56 to 0.67, 0.81 to 0.87, and 0.85 to 0.94, respectively. Compost amounts, subsurface drip and gated furrow irrigation treatments led to apparent decrease in average values of soil bulk density and apparent increase in average values of total porosity, and hydraulic conductivity. Soil pH and EC values decreased by increasing of application rate of compost under all the used irrigation systems. On the other hand, the application of compost treatments led to increase organic matter, total N and available P values of the investigated soil. The yield of corn grains and cobs favorably affected by the applied treatments as the maximum average yield of corn grains were 4.78 and 4.1 t/fed. obtained by recent application under SD and GF irrigation systems, respectively. Whereas the maximum average yield of corn cobs were 0.78 and 0.58 t/fed. obtained by recent application under SD and GF irrigation systems, respectively.