Improvement of crop yield, soil moisture distribution and water use efficiency in sandy soils by clay application

Cultivating sandy soil is a promising solution to o vercome the fight against hunger especially in the developing countries. The main pr oblems of sandy soil are moisture holding capacity and nutrients deficiency. A contai ners experiment was carried out to study the enhancement of water productivity and cro p yield of sandy soils treated with clay. The container size was 31 x 15 x 60 cm with o ne transparent side for visual viewing of the root development beside growth characteristics. The soil with bulk density of 1.5 g/cm 3 mixed with CaCO3 and P2O5 fertilizers was packed in the containers to 50 cm height. Three treatments: contr ol, overlay and incorporate with four replicates were studied. The control treatment was only sandy soil, 4 % by weight of clay was overlay on the surface of sandy soil to constitute the overlay treatment (5.6 kg soil with 21.4 % clay overlay on 28.4 kg sa ndy soil with 93 % sand) while the same percentage of clay was incorporated with the u pper 20 cm of sandy soil to represent the incorporate treatment. All the treatm ents received the same amount of irrigation water and fertilizers during the growing stage. The results indicated that the leaf area in cucumbe r and stem length, stem diameter and number of leaves in maize were increased in the tre atments treated with clay. About 2.5 times of yield was obtained due to those treatm ents compared to the controlled ones, i.e. without treatment. Roots grew intensivel y in the layers treated with clay. The incorporate treatment retained higher amount of wat er compared to those controlled but with small differences compared to overlay trea tment. The water use efficiency and water saving was highly increased by clay appli cation and about 45% -64% of irrigation water could be saved compared with the c ontrolled ones.