EFFECT OF IRRIGATION SCHEDULES AND TILLAGE SYSTEMS ON RICE PRODUCTIVITY AND SOIL PHYSICAL CHARACTERISTICS – A CASE STUDY IN THE NORTH NILE DELTA, EGYPT

摘要

A shortage of fresh water for irrigation and a necessity to search for effective on-farm water management strategies are required for increasing rice water use efficiency (WUE). The current investigation was therefore, aimed at comparing the influence of irrigation intervals and tillage operations. Tillage operations were carried out as main treatments with chisel plough (2- passes) and wet leveling (T1), chisel plough (1-pass) and dry leveling (T2), moldboard plough, disc harrow and then dry leveling (T3) and zero tillage (T4). Rice crop was irrigated as sub-treatments at four intervals at every 3 days (I.e., continuous flooding) (I1), 6 days (I2), 9 days (I3) and 12 days (I4). Two rice cultivars (Giza 177 and Sakha 101) were tested for the experiment. Rice growth in terms of root volume and root / shoot ratio, grain yield and WUE were determined. Soil penetration resistance (SPR) and bulk density (BD) of post-harvest soils were also measured. Irrigation schedules and tillage types had profound effects on the crop and soil parameters. As a result, the longer irrigation periods significantly decreased grain yield and WUE but increased the root volume.