OPTIMIZATION OF VEGETABLE PRODUCTION USING IRRIGATION REGIMES AND ORGANIC FERTILIZERS

Abstract

Vegetable farming is one of the most profitable activities in agriculture, in both the wet and dry season’s cultivation period. It does not only provide farmers with a source of revenue, but it also constitutes an essential source of food for many kinds of households. The objective of the study was to optimize vegetable production using organic fertilizers and irrigation regimes. Three (3) vegetable crops namely, lettuce, beetroot, and okra were used for the study. The experiment was conducted at Nyankpala Campus of the University for Development Studies in Ghana for two (2) seasons i.e., dry and rainy seasons. A 3 × 4 factorial pot experiment was laid out in Randomized Complete Block Design (RCBD) with three (3) levels of irrigation regimes (50, 75, and 100 % based on crop water requirement (CWR) consumed through evapotranspiration (ETc) and three (3) organic fertilizers i.e., compost (CMT), sheep droppings (SHD), cow dung (CWD) applied at 0.5 kg per pot; and no organic fertilizer treatment (CTR) with three (3) replications each. The physicochemical properties of the soil and organic fertilizer used was analyzed before and after the experiment. The experimental soil was sandy loam with dry bulk density between 1.28 - 1.32 g/cm3 , field capacity (FC) at the time of the experiment was calculated as 19.6 %, permanent wilting point (PWP) as 9.1 %, organic carbon (OC) ranged from 1.18 - 1.19 %, pH ranged from 6.15 - 6.21 and electrical conductivity (EC) of 79.5 – 80.3 µS/cm. The crop water requirement of the study vegetables at 100% for lettuce, beetroot and okra was 371.8 mm/dec, 341.6 mm/dec and 257.2 mm/dec respectively. Lettuce weight ranged from 48.7 to 96.7 g with the highest recorded in the pot treated with SHD at 100 % CWR, the leaf number ranged from 15 to 22, yield ranged from 5.01 – 7.38 t/ha with the highest recorded in the pots treated with CWD at 50% CWR respectively. For beetroot, the plant height ranged from 31 – 36 cm with the highest observed in the control pot with 75 % of CWR, the number of leaves ranged from 13 – 15, bulb weight was from 100 - 160 g with the highest recorded in the pots treated with CMT at 100 % CWR respectively and yield of 7.06 – 12 t/ha, with the highest in the pots treated with CMT at 100 % CWR. For okra, the pot treated with CWD at 75 % CWR had the most positive result with plant height from 27.5 – 30.5 cm, the plants with SHD at 100 % CWR resulted in high number of leaves ranging from 23.2 – 27.5, while the plants with CWD at 100 % CWR resulted in highest fruit weight of 12.5 – 13.6 g. In terms of fruit diameter and length, the pots treated with SHD recorded the highest measurements in the three irrigation regimes. The highest number of fruits was recorded in the plants treated with SHD at 50 % CWR with 13 pods per plant. The study revealed that organic fertilizer application enhances the growth and development of vegetables and can help increase water use efficiency by conserving soil moisture. Hence, in water scares areas, deficit irrigation with organic fertilizer can be adopted in the production of high valued vegetables and improvement in soil properties.