M.S. lslam
Bangladesh Agricultural Research Institute, Joydebpur, Bangladesh
Soil Nutrient Status, Affecting Productivity of Pulses, Major and Potential Pulse-Growing Areas
Crop-Soil-Water Management
General Soil: Types The general soil types of the pulse-growing areas include mainly noncalcareous gray floodplain soils, noncalcareous dark gray floodplain soils, calcareous dark gray floodplain soils, calcareous gray floodplain soils, and gray piedmont soils.
Nutrient and Moisture Status: Noncalcareous alluvium These soils are slightly acidic to near neutral. Their pH ranges from 5.9 in Shaghatta soil series to 6.5 in Bonarpara and Kanuia series. Organic matter content of these soils is around 1.0%. However, levels as low as 0.57% are present in Sarikandi soil series. The calcium and magnesium content of these soils is satisfactory. Ca values range from 3.0 to 7.1 meq 100 g-1 of soil while Mg values range from 1.41 to 1.73 meq 100 g -1 soil. The potassium status is variable. K values may be considered low, and a liberal dressing of potash is necessary to obtain optimum yields. Nitrogen is deficient in all soil series with N H4 - N values ranging from 8-17 µg g-1 soil. Phosphorus content is quite variable. Bonarpara and Sariakandi soil series contain phosphate values below critical level. Other soil series may be classed as medium with respect to phosphate content.
Nutrient Requirements: Nutrient requirements of different pulse crops depend on initial fertility status as well as yield goals. In Bangladesh pulse crops are generally grown without any fertilizers and manures. Information on nutrient requirements of various pulse crops is scanty. However, a short review on current information is furnished below.
Chickpea: This crop can meet its nitrogen requirement by symbiotic fixation of atmospheric nitrogen. Since Bangladesh soils are critically deficient in nitrogen, a basal application of 20 - 30 kg N ha-1 has been found to increase the seed yield of chickpea ( B A R C 1981 to 1984). Response of chickpea to phosphate fertilization is high. Khanom and Islam (1984) obtained yield increases (31%) by application of 30 kg P2O5 ha-1. A further increase of about 15% was reported by the additional application of 30 kg P2O5 ha-1. Islam et al. (1985) observed the beneficial effect of potash fertilization on grain yield of chickpea in calcareous brown floodplain soils. The sulphur progressively increased the pod and straw yields of chickpea. with increasing rates approaching 25 kg S ha-1 (Talukder et al. 1984). In the case of micronutrients, responses to boron and zinc were observed in the noncalcareous gray floodplain and calcareous brown floodplain soils. Boron addition helped in forming nodules and thereby increased yield. Further investigations are in progress. Zinc application at the rate of 5 kg ha-1 increased grain yield from 0.81 t ha-1 in the control plot to 1.02 t ha-1 in a treated plot.
Lentil Very little work has been done on this crop under Bangladesh soil conditions. Khanom and Islam (1983 ) observed that the application of phosphate (up to 60 kg P2O5 ha-1) increased the grain yield of lentils in the grey floodplain soil of Jamalpur. Phosphate fertilization had no effect on percent N and P content. In calcareous brown floodplain soils, Islam et al (1985) obtained beneficial effects of 90 kg K2O ha-1 along with N30 P60 in increasing the grain yield. In other trials in a gray floodplain and calcareous brown floodplain soils, phosphate and potash application significantly increased grain yields at both locations. Sulphur and zinc application had little effect. In another missing nutrient trial conducted in calcareous brown floodplain soils of Rajshahi the significant combined influence of N, P, K, S, Zn, Cu, B, and Mo, was noted over the control plot.
Fertilizer Recommendations On the basis of available information Islam and Amin (1988) suggested fertilizer doses for various pulse crops in Bangladesh. Soil fertility and yield goals were the main criteria in formulating such recommendations.
Advances in Pulses Research in Bangladesh Proceedings of the Second National Workshop on Pulses 6-8 Jun 1989 Joydebpur, Bangladesh
Report/Proceedings