Tuber Depth and Yield Response of Tiger Nut (Cyperus esculentus) to Soil Texture and Rates of Poultry and Pig Manure

A pot experiment was conducted to evaluate tuber depth and weight of tiger nut produced in loamy fine sand and sandy clay soil using 0, 200, 300 or 400 g per pot of poultry or pig manure in a 2 × 2 × 4 factorial experiment arranged in completely randomized design and replicated three times.  Total tuber weight and weight of tubers at 10 cm were significantly increased by application of manure compared with the control. Significant interaction of soil texture X manure types X manure rates was recorded on weight of tubers at 20 cm. Percentage of tubers at 0-10 cm was 90.6-92.1% (91.5-93.6% tuber weight); while 6.68-8.96% of the tubers (5.49-8.47% tuber weight) were harvested between 10-20 cm soil depth; only 0-0.94% of the tuber weight was harvested beyond 20 cm depth. Pig manure had positive effect on tiger nut productivity on loamy fine sand and sandy clay soil, while with poultry manure tiger nut productivity was enhanced on sandy clay soil; 300 g of pig or poultry manure produced similar weight of tiger nut tubers and is considered optimum for tiger nut productivity. Sandy clay and loamy fine sand had similar effect on depth and yield of tiger nut. More than 99% of the tubers were confined to 0-20 cm soil depth. Information on how deep the tubers of tiger nut can grow in soil of different texture and fertility status will enhance precise harvesting.