Soil Calcium, Magnesium and Potassium Status: Concern for Rice Production in Bangladesh under Unfavorable Ecosystems

Jatish C. Biswas; Md Mozammel Haque; P. K. Saha

Jatish C. Biswas Soil Science division, Bangladesh Rice Research Institute, Gazipur-1701, Bangladesh.
Md Mozammel Haque Soil Science division, Bangladesh Rice Research Institute, Gazipur-1701, Bangladesh.
P. K. Saha Soil Science division, Bangladesh Rice Research Institute, Gazipur-1701, Bangladesh.

Keywords: Agricultural ecological zone, Native nutrient ratio, Rice yield

Abstract

Unfavorable ecosystems in Bangladesh are under intense pressure of crop production and climate change impact; although the relationships of indigenous soil nutrients ratios with crop performance are yet to be fully explored. Experiments were conducted under submergence and cold prone areas (agricultural ecological zone, AEZ-3), drought and cold prone areas (AEZ-26), non-saline tidal flood ecosystem (AEZ-13), char and saline prone ecosystem (AEZ-18) and haor ecosystem (AEZ-21) for evaluating rice grain yield with native nutrients ratios. Synergistic and antagonistic relationships were observed in different AEZ depending on indigenous nutrient ratios. The K:Ca and K:Mg ratios were playing significant negative role in AEZ-18 for wet season rice yield; but K:Ca played synergistic role in AEZ-3 and AEZ-26. In dry season, K:Ca ratio was acting antagonistically in AEZ-3 and AEZ-13 and K:Mg in AEZ-13. The ratio of K to Ca was acted positively for dry season Boro rice production in AEZ18 and AEZ-26. Similarly, K:Mg ratio was playing synergistic role for Boro rice yield in AEZ-3, AEZ-18 and AEZ-26. Application of fertilizers improved dry season rice yield significantly in all AEZ except AEZ-18 compared to indigenous soil fertility. It is concluded that indigenous soil nutrient ratios play a vital role in improving rice yield under unfavorable ecosystems in which more K fertilizer need to be applied for satisfactory rice yield in dry season.