TITLE:
Heterogeneity and Spatial Distribution of Inorganic Nitrogen as Nitrate (N-NO3) in Two Soils Dedicated to Green Dwarf Coconut in Guerrero, Mexico
AUTHORS:
Jorge H. Ramírez-Silva, Matilde Cortazar-Rios, Genovevo Ramírez-Jaramillo, Carlos M. Oropeza-Salín, Dinosca N. Rondón-Rivera
KEYWORDS:
Kriging, Foliar N, Deficiency, Heterogeneity, Critical Level
JOURNAL NAME:
Open Access Library Journal,
Vol.9 No.11,
November
8,
2022
ABSTRACT: The productivity of coconut in Guerrero, Mexico has decreased substantially. The experts recommended a diagnosis of the soil fertility before launching a sound reforestation program. The introduction of Green Dwarf Coconut (GDC) due to its high productivity was suggested; however, nitrogen (N) was of higher interest since GDC is a highly demanding material. In this work, the contents, in parts per million (ppm), of nitrogen (N) as nitrate (N-NO3) as well as its chemical variability (Coefficient of Variation) and spatial distribution (Kriging method) was determined at 0 - 30 and 30 - 60 cm deep in the soil. Two GDC commercial plantations were selected and the study was complemented with foliar N (%) analysis. Two farms: Las Tunas (LT) of 9 hectares and Aguas Blancas (AB) of 5 hectares were sampled taking one point per hectare at both depths, one meter from the trunk. In LT, the overall average of N-NO3, at 0 - 30 cm, was rated as MEDIUM and at 30 - 60 cm as LOW. On the other hand, in AB the general average of N-NO3 was graded as LOW at both depths. The two farms showed important chemical heterogeneity as indicated by the HIGH CV’s (%). Regardless of the specific values of N, in LT the spatial distribution of N seems to be the same between both depths with an approximate area of 20% classified as LOW (14 - 18 ppm) and 80% as MEDIUM 20 - 28 (ppm). On the other hand, in AB the spatial distribution was contrasting between depths. At 0 - 30 cm deep, an approximate area of 15% was rated as LOW and 75% as MEDIUM whilst at 30 - 60 cm deep, 70% was LOW, 28% MEDIUM and just 2% HIGH. Although both farms showed LOW foliar N contents, as compared to the critical range of 1.8% - 2.0%, AB was the one reporting the lower N value of 1.16% vs. LT with 1.44%, both in deficiency levels.