World Journal of Agricultural Sciences 8 (4): 351-358, 2012 ISSN 1817-3047 © IDOSI Publications, 2012 DOI: 10.5829/idosi.wjas.2012.8.4.1635 Corresponding Authors: C. Nwite John, Department of Crop Production Technology, Federal College of Agriculture, Ishiagu, P.M.B. 7008 Ishiagu, Ivo L. G. Area, Ebonyi State, Nigeria. 351 Sawah Rice System, a Technology for Sustainable Rice Production and Soil Chemical Properties Improvement in Ebonyi State of Southeastern Nigeria J.C. Nwite, S.E. Obalum, C.A. Igwe, E.N. Ogbodo, C.I. Keke, B.A. Essien and T. Wakatsuki 1 2 2 3 1 1 4 Department of Crop Production, Federal College of Agriculture, 1 Ishiagu P.M.B. 7008, Ivo L.G.A, Ebonyi State, Nigeria Department of Soil Science, University of Nigeria, Nsukka, Nigeria 2 Department of Soil and Environmental Management, Ebonyi State University, Abakalik, Nigeria 3 Faculty of Agriculture, Kinki University, Nara 631-8505, Japan 4 Abstract: The soils in Ebonyi State agro-ecological zones of southeastern Nigeria are plagued with characteristics that impede optimal crop production. Failures in agricultural development in this part of southeastern Nigeria may have been caused by the inability of the farmers to develop the abundant inland valleys for such crops like rice using appropriate water management systems. In order to arrest the declining productivity of the inland valley soils in these zones, four different organic sources (Rice husk; Rice husk ash; Poultry droppings at 10 t/ha and NPK 20:10:10 at 400 kg/ha) were used in four different sawah environments including farmers environment (Complete sawah; Incomplete sawah; Partial sawah and farmer’s environment) in two inland valleys in southeastern Nigeria to evaluate their effects on some soil properties and rice grain yield. Sawah is generally described as a controlled water management in the field where the soil is expected to be puddle, leveled and bunded in order to impound water provided by rain water or by rise in the level of a river in an inland valley. The field layout was Split-plot in a randomized complete block design (RCBD) in which the five treatments (including the control) were replicated three times within the four sawah environments including the farmer’s field. The field was demarcated into four main plots with five sub-plots in each using 0.6m raised bunds except in the main plot used as farmer’s field. The four main plots were prepared and managed according to specifications of the study. The bunds have inlet and outlet channels through which water is introduced into the field from a water source and excess drain from the field, respectively. The test crop was a high yielding rice variety (Oryza sativa var. FARO 52/WITA 4). The rice seedlings were transplanted at the age of three weeks after nursery. Soil properties tested were soil organic carbon, total nitrogen, pH, CEC, EA and Base saturation, while the grain yield of rice was also measured. The results showed that soil pH, OC and TN were statistically improved within sawah managed environment in both locations. The amendments also improved the pH, TN, CEC and base saturation during the period. Also rice grain yield was statistically increased by both sawah managed environments and the soil amendments, with complete sawah environment amended with poultry droppings giving the highest significant increase in the yield of 7.5 tons per hectare. Key words: Sawah environment Soil properties Rice grain yield Soil amendment INTRODUCTION Southeast for Agricultural use, these areas are yet to be Increasing food production both to meet in-country Poor soil fertility and inefficient weed and water requirements and to help the world overcome food crisis control are the major constraints to proper utilization of is one major issue facing Nigeria today. In spite of the these inland valleys for sustainable rice-based cropping. potentials of Nigeria inland valleys especially the The soils of Southeastern Nigeria particularly, exploited fully.