The potential production ofdifferent lands varies depending on the quality of the.land. The land suitability class S4; moderately suitable and S5; marginally suitable lands yielding 5,000 to 10,000 nuts ha–1 yr–1 and 2,500 to 5,000 nuts ha–1 yr–1 for coconut respectively are regarded as low potential productivity lands. These lands have limitations which are moderately severe and reduce the level of coconut productivity. Thus, these lands require inputs like fertilizer and agricultural practices like contour drains or terracing, husk pits, cover crops and mulch around the palms to break even cost and bring about profit to moderate level. Fertlizer application is one of the important inputs for such lands. The information on macro and micronutrient removal by Typica x Typica (CRI 60) coconut palms and required fertilizer input to compensate the loss of nutrients in low potential productivity lands are not available. Therefore, the objective of this study was to estimate the macro and micronutrient removal by coconut palms in low yielding lands and to compare nutrient removal with fertilizer inputs and soil reserves.
Harvested nuts, fallen fronds and fallen inflorescences were collected monthly interval for three years from ten coconut palms of Typica x Typica (CRI 60) grown on moderately suitable Boralu series soil (Red Yellow Podzolic). The macro and micronutrients in plant components and nutrient reserves in experimental site were determined. The results reavealed that the major nutrient removed by all plant parts were 164,53,37; 22,19 and 9.85 kg–1 ha–1 yr–1 for K, N, Na, Ca, Mg and P respectively. The amount of N, P, K, Ca and Mg applied annually as fertilizers were 58, 11.5, 125.9,69.9 and 19 kg–1 ha–1 respectively. Except K and Mg, the other macronutrients, input by application of fertilizer slightly exceeds the nutrient removal. The N, P, Ca and Mg reserves of soil was high and would not deplete rapidly. The K input by application of 3.3 kg of APM fertilizer mixture was about 76.7 % of the K removal. This leads to depletion of exchangeable K pool rapidly, if the harvested nuts and fallen plant components are all removed from the plantation. Hence, the depletion should be compensated for either by adding extra 80 kg ha–1 of Muriate of Potash or recycling of fallen fronds and residues of the inflorescences or mulching the manure circle using fresh coconut husks or addition of organic manure.
The mironutrient removed through all plant parts were 0.93, 0.53, 0.28, 0.15 and 0.09 kg–1 ha–1 yr–1 for Fe, Mn, Zn, B and Cu respectively. The reserves of available Fe, Mn, Cu and Zn in Boralu series soil was very high and the gap between the soil reserves and the plant removal rates were high. Hence, micronutrient containing fertilizers would not be required as the depletion of micronutrient reserves in soil would not occurre significantly.
Wijebandara DMDI, Kurudukubura CPA, Panditharathna DP. Nutrient removal through plant components of low yielding coconut plantation. COCOS. 2016;21:1–13. DOI: http://doi.org/10.4038/cocos.v21i0.5802
Wijebandara, D. M. D. I., Kurudukubura, C. P. A., & Panditharathna, D. P. (2016). Nutrient removal through plant components of low yielding coconut plantation. COCOS, 21, 1–13. DOI: http://doi.org/10.4038/cocos.v21i0.5802
Wijebandara, D. M. D. I., C. P. A. Kurudukubura, and D. P. Panditharathna. 2016. Nutrient removal through plant components of low yielding coconut plantation 21: 1–13. DOI: http://doi.org/10.4038/cocos.v21i0.5802