IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS) e-ISSN: 2319-2380, p-ISSN: 2319-2372. Volume 13, Issue 10 Ser. III (October 2020), PP 45-51 www.iosrjournals.org DOI: 10.9790/2380-1310034551 www.iosrjournals.org 45 | Page Combined Rice Mill and Poultry Wastes Affect Some Soil Chemical Properties and Water Melon (Citriluslanatus) Yield In A Derived Savanna Of Obubra, Southern Nigeria Kekong, M. A. Department of Agronomy Cross River University of Technology, Calabar, Nigeria Abstract: Background: Organic nutrient sources are promising resources for sustainable crop production. The variability in nutrients content of organic materials and their time and rate of release to crops pose a challenge. The C:N ratio is a major determinant in the choice of organic materials for crop nutrition and soil amendment. The higher the C:N ratio the slower the process of mineralization and the delay in nutrients release. Poultry droppings is known for its lower C:N ratio compared to rice mill waste. Combination of these organic wastes may improve the nutrients efficacy and release efficiency of rice mill wastes noted for its high ratio.The study evaluated the effect of combination of Rice mill waste (RMW) with Poultry droppings (PD) on some soil chemical properties and yield of Water melon. Materials and Methods:Six treatments consisting of Control (no manure), RMW 10t ha -1 , RMW 10t ha -1 + PD1t ha -1 , RMW 10t ha -1 +PD 2t ha -1 , RMW 10 t ha -1 + PD 3 t ha -1 and RMW 10 t ha -1 +PD 4t ha -1 were laid out in Randomized complete block design (RCBD) in three replicates. Each experimental plot unit measured 5m x 4m and a gross experimental plot of 27m x 22m (594m 2 ) or 0.059ha. Results obtained indicated that there were significant differences (P<0.05) among the combined manures and the sole and control. Results: All RMW 10 t ha -1 + PD 1, 2, 3and 4 t ha -1 produced higher number of fruits per plant in both years (10.10, 10.02, 11.03 and10.82 respectively for 2017 and 8.20, 10.8, 10.30 and 11.1 fruits per plant respectively in 2018). RMW 10 t ha -1 + PD 3 t ha -1 and RMW 10 t ha -1 +PD 4t ha -1 produced heaviest fruits (4.2kg and 4.4kg mean weight of each fruit respectively in 2017 and 4.3kg and 4.8kg respectively in 2018). Fruit yield per unit area was also highest in these same treatments with yields of 46.8 t ha -1 and 47.2 t ha -1 respectively in 2017 and 48.1 t ha -1 49.4 t ha -1 respectively in 2018 while the least yield was obtained in the control and the sole RMW. SOC, total N, Avail. P and exch. Ca were increased by all combined manures over the control and the sole RMW that produced lower values. Conclusion: Combined application of RMW 10t ha -1 + PD 3 t ha -1 and RMW 10 t ha -1 + PD 4 t ha -1 are suitable for optimum yield of Water melon and improvement of soil fertility in this location. Key Words: Ricemill waste, poultry waste, watermelon, soil properties, derived savannah, Nigeria --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 31-10-2020 Date of Acceptance: 13-11-2020 --------------------------------------------------------------------------------------------------------------------------------------- I. Introducton Water melon (Citriluslanatus (Thunb) MatsumNakai) is a plant in the family Cucurbitaceae. The crop‟s origin has been traced to Africa and regions of the Kalahari and Sahara Deserts [1] and Sahelianzone of West Africa [2]. It is one of the world‟s most important and cherished vegetable as it is grown for both its fruit and vegetative parts [3]. The fruit vegetable is so nourishing with high water content and significant amount of sugar, Vitamins A,B,C[2]. In southern Nigeria there is no information on its production to meet the vegetable demand of this crop. At commercial production, watermelon cultivation is confined to the drier savannah region of Nigeria [4] where the crop is thought to do best possibly due to the prevailing climate of the region. There are divergent views on the crop‟s soil nutrients needs.[5]stated that water melon can be grown with little or no fertilizer in soil. In other findings, [6];[3] reported that the crop is a heavy feeder and high demander for N. The source of the nutrient has posedsome challenges on the quality and yield of crop as well as soil reaction. [7] reported that inorganic fertilizers has depressing effect on yield of water melon as it causes reduction in number of fruits, delays and reduces fruit setting which subsequently delays ripening. The practice of inorganic fertilizers in Nigeria has been implicated in negative impacts on soil and farmers economy. [8]reported physical and chemical deterioration of our fragile soil; prolong use deteriorates surface soil characteristics and affects nutrients availability and uptake by plants [9]. The cost and scarcity of inorganic fertilizer due to removal of all subsidies by government [10]makes fertilizers unaffordable to resource-poor farmers.