Ameliorative Role of Zn, K, and Gypsum on Maize Growth under Alkali Soil Conditions1
- U. C. Shukla and
- A. K. Mukhi2
Information is needed on the ameliorative role of Zn in relation to gypsum and K on plant growth under alkali soil conditions. A greenhouse experiment was conducted, growing maize (Zea mays L.) as an indicator crop for 45 days. Treatment combinations of three levels of Zn (0, 5, 10 ppm), and three levels of K (0, 50, 250 ppm) were superimposed on a normal, an alkali, and a gypsum-treated alkali soil.
Shoot dry matter yield in alkali soil was only 35% of the normal soil. The application of 5 ppm Zn, 250 ppm K, and gypsum to the alkali soil resulted in the recovery of yield to 91, 75, and 70% of that obtained in the normal soil. The highest yield was recorded with the application of 10 ppm Zn, 250 ppm K, and gypsum to the alkali soil, which was 14 and 59% more than normal, and Zn-treated alkali soils, respectively. The magnitude of Zn and K response in alkali soil was less after gypsum treatment. Responses to the above nutrients were also negligible in the normal soil.
Zinc concentration decreased under alkali soil conditions. Gypsum and K enhanced Zn utilization by the plans. Shoot Na was highest in the alkali, and lowest in the normal soil. Zinc decreased Na. The highest decrease was in *e alkali soil. An application of 250 ppm K also decreased Na. The effectiveness of Zn, K, and gyp sum treatments in decreasing Na concentration was diminished when any of the above two treatments were applied together.
The highest shoot K was in the normal soil, and was similar in the alkali and gypsum-treated soils. The highest increase in shoot K with K was ha the alkali and gypsum-treated alkali soils. Zinc decreased shoot K in the alkali soil. Shoot Ca decreased with Zn or K in the normal soil, but increased in the alkali, and at their low levels in the gypsum-treated soil. Interrelationships between Na, Zn/K, and Ca, showed decreased effectiveness when applied together, on Ca concentration. Accumulation of shoot Mg was more in the alkali than in other soils when K or Zn were not applied. The antagonism between K and Mg was evident. Antagonism between K and Ca in relation to Mg concentration was also noted.
The yield increase in alkali soil with Zn was associated with the enhanced uptake of Zn and Ca, decreased concentration of Na, and widening of Ca/Na and K/Na ratios. The increase in yield with K, and gypsum treatments was also greatly associated with the enhanced uptake of Ca and other plant nutrients.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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