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Asian Journal of Agriculture and Development (AJAD) - Call for papers!

Influence of Silicate and Sulfate Sources on Phosphorus Sorption and Corn Yields

(Philippines), Doctor of Philosophy in Soil Science (University of the Philippines Los Baños)

Dissertation Abstract:

 

The potential of competitive anion adsorption for phosphate using siIicate and suIfate as a possible management strategy to increase phosphate availabiIity to corn was tested on two extremely acidic, phosphorus (P)-deficient soils, namely: Luisiana clay and Adtuyon clay.

This study was conducted to: 1) evaluate the effects of calcium, magnesium, potassium, and sodium silicates on P sorption, available P, and dry matter yield of corn: 2) to evaluate the effects of calcium, magnesium, potassium, and sodium sulfates of P sorption, available P, and dry matter yield of corn; and 3) to evaluate the effects of calcium silicate and calcium sulfate on available P, soi l pH, exchangeable aluminum, and grain yield corn.

Application of 250 ppm and 500 ppm siIicate in the form of calcium silicate on Luisiana clay decreased the P sorption maximum of the soil from 2.4522 to 2.4237 and 2.2969 mg P g·1, respectively. Other silicate sources had lesser effect than calcium silicate in decreasing the P sorption maximum of the soil. Sulfate application resulted in a very slight decrease in the maximum P sorption of the soil.

On Luisiana clay not fertilized with P, application of different silicate and sulfate compounds did not increase dry matter yield of corn but P application resulted in significantly higher dry matter yield. Combined application of 160 ppm P and 250 ppm silicate (calcium silicate and potassium silicate) significantly increased dry matter yield of corn.

On Adtuyon clay, the application of either 60 kg P20 5 /ha, 120 kg PP/ ha, or 250 kg silicate/haas calcium silicate significantly increased with the application of either 250 kg silicate/ha as calcium silicate or 120 kg P20 / ha. The application of silicate and sulfate alone or in combination with P did not increase soil P test value at silking stage over the P treatments.

Silicate and sulfate application alone, however, resulted in a significantly higher concentration of P in corn plants. Grain yield and P uptake of corn increased significantly with the appl ication of either 250 kg silicate/haas calcium silicate, 100 kg sulfate/haas calcium sulfate, 60 kg PP/ ha or 120 kg P20 / ha. Silicate and sulfate application alone slightly reduced P sorption, did not increase soil P test values but increased soil pH, decreased exchangeable aluminum, increased P concentration in corn plants, and increased P uptake and grain yield of corn.