Synthesis of calcium phosphate from golden apple snail (Pomacea canaliculata) shell to replace commercial phosphorus fertilizer used in sugarcane (Saccharum spp.) cultivation
Abstract:
This thesis studied the synthesis calcium phosphate from golden apple snail shells for replacement chemical fertilizer used in sugarcane cultivation. The two synthesis methods were simple calcium phosphate synthesized from golden apple snail shells and calcium phosphate synthesized from micro particles shell. Base on the analysis of synthesized compounds from both methods, it was found that the first method resulted in calcium phosphate compound in the form of monocalcium phosphate monohydrate (MCPM) and the second method was in the form of dicalcium phosphate dihydrate (DCPD) with available phosphate (P2O5) contents at 55.91 and 28.32%, respectively, solubility in 2% citric acid were 91.42 and 74.02%, respectively. In the experiment of sugarcane cultivation, MCMP was used for substitute phosphorus containing in standard commercial chemical fertilizer grade 15-15-15 with the rate of 100 kg/rai for the second ratoon and the third ratoon grown in lowland area, as well as the first ratoon and the second ratoon grown in upland area. Those shell fertilizers contained urea fertilizer, MCPM, potassium chloride at 32.60, 27.40 and 25.00 kg, respectively, which were equal to commercial chemical fertilizer grade 15-15-15. The cost of commercial chemical fertilizer and golden apple snail shell fertilizer were 1,620.00 and 1,214.44 baht/rai, respectively. The study using both fertilizers in sugarcane cultivation in sugarcane production season
2017/2018 with the second ratoon and the third ratoon grown in lowland area revealed that the properties of cultivated soil after sugarcane harvesting were different (P<0.05) in pH, available P, and soil exchangeable Ca. The shell fertilizer was accumulated in the soil higher than that ofchemical fertilizer, which the soil parameters in shell fertilizer and chemical fertilizer were pH 5.93 and 6.24, available P 62.07 and 53.07 mg/kg, exchangeable Ca 406.67 and 354.09 mg/kg, respectively. The EC, OM, exchangeable K and Mg of soil were not significant (P>0.05) between both types of the fertilizers which the average soil parameters were 189.88μS/cm, 1.86%, 57.90 and 47.68 mg/kg, respectively. The growths of sugarcane measured at the age of 4 and 8 months were not significant (P>0.05) in all parameters studied; height, stem diameter, number of tree per rai and leave greenness which the average values of 8 months were 2.64 m, 25.90 mm, 11,028.25 tree/rai and 42.49 SPAD value, respectively. The nutrient accumulation in sugarcane leaves during the age of 4 and 8 months were not significant (P>0.05) of fertilizer types on the amount of N, P, K and Mg which the average parameters of 8 months were 1.77, 0.19, 1.22 and 1.84%, respectively. However, calcium accumulated in sugarcane leaves for both 4 and 8 months when utilization shell fertilizer (0.20 and 0.17% respectively) was significantly (P<0.05) higher than that of chemical fertilizer (0.12 and 0.11% respectively). The sugarcane cultivation using both fertilizers in sugarcane cultivation with the first
ratoon and the second ratoon grown in upland area found that the properties of cultivated soil after sugarcane harvesting were not significant different (P>0.05) in all parameters except the age of sugarcane stubble which there was significant different (P<0.05) aspect of pH in soil. The pH in soil of the area cultivated the first ratoon was higher than that of the second ratoon which the
soil pH were 6.35 and 6.05, respectively. The average of EC, OM, available P, exchangeable K, Ca and Mg of soil were 131.75 μS/cm, 1.83%, 96.90, 126.16, 146.51 and 50.58 mg/kg, respectively. The growths of sugarcane measured at the age of 4 and 8 months. As the result show that only the number of tree per rai at the age of 8 months had different (P<0.05) between both types of the fertilizers. The value of shell fertilizer was higher than that of chemical fertilizer which the values were 13,585.03 and 12,961.95 tree/rai, respectively. The height, the stem diameter and the leave greenness at the age of 8 months were 2.40 m, 26.93 mm and 43.78 SPAD value, respectively. The nutrient accumulation in sugarcane leaves using fertilizer types on the amount of N, P, K and Mg during the age of 4 and 8 months had not significant (P>0.05), which the average values of 8 months were 1.76, 0.19, 1.35 and 1.74%, respectively. However, calcium in sugarcane leaves for both 4 and 8 months when utilization shell fertilizer (0.20 and 0.22%
respectively) was significantly (P<0.05) higher than that of chemical fertilizer (0.13 and 0.12% respectively). The production of harvested sugarcane at the age of 12 months was not significant (P>0.05) between parameters in both quantity of fresh sugarcane and the quality of sugarcane or commercial cane sugar (CCS). The yield of the first ratoon was 20.7-21.58 ton/rai, the second ratoon was 19.83-21.25 ton/rai and yield of the third ratoon was 18.56-18.84 ton/rai. When the age of sugarcane stubble increased, the yield and the quality was decreased. From this study, the average profit of the first ratoon, the second ratoon and of the third ratoon of sugarcane were 17,793.69, 16,660.14 and 13,474.74 baht/rai, respectively. The benefit/cost ratio of the first ratoon, the second ratoon and the third ratoon of sugarcane were average at 2.64, 2.48 and 2.21,respectively.