Neem seed cake nitrogen fertilizer equivalencies as assessed by sorghum at Samaru, northern Nigeria
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Date
2020-12
Journal Title
Journal ISSN
Volume Title
Publisher
Organic Agriculture Project In Tertiary Institutions In Nigeria(Oaptin)
Abstract
Application of organic materials is imperative for soil and crop sustainability of the generally inherent low
fertility soils in the northern guinea savanna of Nigeria. Consequently, a field study was set up at the Institute
for Agricultural Research (IAR), Zaria during the cropping seasons of 2009 and 2010 to establish the
chemical fertilizer equivalent value of neem seed cake (NSC), and also investigate rainfall pattern in relation
to evapotranspiration rates in the region as these two weather determinants affect the planting dates. The
experiment consisted of sorghum plots to which milled NSC (with % N greater than 3) and urea (inorganic N
source) were applied. Factorial combination of four levels of NSC (0, 1, 2 and 4 t ha-1) and four rates of
chemical fertilizer package (0, ½, ¼ and full recommended fertilizer rates of 64 kg N, 32 kg P O , 32 kg K O 2 5 2
for sorghum), making a total of sixteen treatments laid in a randomized complete block design and replicated
three times. Results obtained for the cumulative above ground biomass yield in the two-year study indicated
that a combination of both NSC and inorganic nutrient source gave higher sorghum biomass yield than when
each was applied separately. Although, the 1 and 4 tonnes levels of NSC gave grain yields that were higher
than when in combination with NPK, none of the NSC-amended plots recorded a grain yield that was equal
to or greater than the recommended optimum inorganic fertilizer rate for sorghum in the region. On the
average, the nine treatment combinations of NSC and NPK gave fertilizer equivalent values for the nitrogen
contained in them ranging from 35.09 to 60.08. It is therefore recommended that NSC be used
complementarily with mineral fertilizer as a source of nitrogen in the ratio 1: 0.25
Description
Keywords
Mineral-N, N-recovery, neem seed cake, nitrogen fertilizer equivalent, sorghum
Citation
Journal of Organic Agriculture and Environment (JOAEN) 8: 42 – 54.