A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development

Thesis (M.Sc.) - Asian Institute of Technology, 2000

The experiment was conducted in highly acidic sandy loam soil at the Potato Breeder Seed Production farm under the Bangladesh Agricultural Research Institute, Debigonge, Panchogar during December' 99 to March 2000. In order to investigate the effect of lime and potassium on soil pH, nutrient availability in soil, concentration of haulms and tuber and their uptake as well as tuber yield and economic return. The experiment was conducted in 4x4 factorial design with three replicates for each treatment combination. The tested factors were application rates of lime (0, 0.5, 1.0 and 2.0 t/ha) and potassium (0, 60, 80, and 100 K, kg/ha). The treatment combinations were allocated to experimental plots in Randomized Complete Block Design. Liming significantly increased soil pH from 4.67 to 4.70 and decreased exchangeable acidity from 0.62 to 0.12 and 0.60 to 0.09 meq/100 g of soil at both 60 and 105 days after liming, respectively. Liming significantly increased percent total nitrogen, percent organic carbon, available phosphorus, potassium, calcium, magnesium, sulphur and zinc availability in soil. Lime significantly increased the concentration of nitrogen, phosphorus, potassium and calcium in both haulms and tubers. Lime slightly decreased magnesium concentration in haulms and had no effect on tubers. Potassium availability increased significantly with increasing levels of potassium as well as lime. Application of lime and potassium significantly increased total dry matter yield from 4.18 t/ha to 7.43 t/ha and total uptake of nutrients from the soil solution. Liming increased percent foliage coverage, plant height, stem per hill, percent tuber grade (A, 28-55mm) and tuber yield. Lime 2 t/ha and potassium 100 kg/ha (L3K3) gave highest yield (33 .54 t/ha) followed by lime 2 t/ha and potassium 80 kg/ha (L3K2) (31.91 t/ha) and lime 1 t/ha and potassium 100 kg/ha (L2K3)(3 l.64 t/ha) respectively. Economic return was highest with (L3K3) higher level of lime and potassium (57,750 Taka/ha) (1110.58$) followed by L2K3 (53,530 Taka/ha) 1029.42$) and LJK2 (52,760 Taka/ha) (1014.62$) treatments. The lowest return (12,590 Taka/ha) (142.12$) was obtained from control. A second order polynomial regression revealed positive relationship among the total nitrogen, potassium, calcium, and magnesium uptake and total dry matter yield. The relationship among nitrogen, potassium and calcium uptake and dry matter yield were more prominent.