Soil Organic Matter and Nitrogen Content as Related to Coconut Nutrition in Guerrero, Mexico

The state of Guerrero in Mexico is the main coconut copra producer with 84,881 hectares and employing more than one million wages annually. However, the production is facing very important and continuous losses due to aging of palms and a lack of technological options to enhance productivity. Farmer’s soils are linked to important problems of low fertility; and the studies to understand the relationship between soil nutrients supply and coconut nutrition are practically unknown. Considering the importance of an optimum nutritional balance for high sustainable productivity of coconut and the Organic Matter (OM) being the main source of Nitrogen (N), as the most important essential nutrient, it was fundamental to quantify both OM and N soil (0 - 30 and 30 - 60 cm deep) as related to the nutritional status of the crop in fifteen plantations from Costa Chica and Costa Grande regions. Critical levels of OM (%), inorganic N as NO-3 (ppm) and Total N (%) in leaves, suggested by the literature, were considered as reference values. Soil properties were considerably heterogeneous among localities. Total average of soil OM (%), and N-NO-3 in both Costa Chica and Costa Grande were quite low at both depths. The total average of OM in Costa Chica was almost the same at both depths with 1.37% and 1.33% respectively and as for Costa Grande the total average of OM varied from 1.29 to 0.71, all below the reference Medium Value of 1.6% to 3.5%. The same deficiencies trend was shown by the foliar N contents (%) where N fluctuated from 1.18% to 1.77%, in Costa Chica and 0.94% to 1.72% in Costa Grande. The best correlation model to better explain the relationship between soil attributes and Foliar N was found when the soil N-NO3, at 30 - 60 cm deep, was compared to the Foliar N in Costa Chica.