Carbon capture and seasonal ‘C’ offset by Foeniculum vulgare grown with N, FYM and their integration

Abstract

Field experiments were carried out on Typic Haplustepts soil having texture sandy loam with various nitrogen levels i.e. 0, 40, 60, 80, 100, 120 kg ha-1 and also integrated use of N + FYM levels taking fennel (Foeniculum vulgare) variety AF-1 as test crop. These treatments were compared with control. Results revealed that seed yield and biomass increased with increasing doses of N levels which was > 1.5 times more with 120 kg N as compared to control. Likewise N+FYM also gave more yield than their individual applications. Carbon content was lower and accumulation in seed, stover including total uptake was higher beyond the 60 kg N ha-1. Carbon content was lower in stover with higher dose of N + FYM and the accumulation in seed and stover was higher. Carbon captured by fennel was more with 12 t FYM applied either with 40 or 80 kg N ha-1. Total or net soil carbon pool was more with higher levels of N, FYM and their combinations. Net carbon offset by the crop and soil in a season was more beyond the 60 kg N or either level of FYM and also in combination with N. Mean carbon offset by fertilizer N was 4.8 t ha-1 and 5.1 t ha-1 by N + FYM. Interestingly carbon content in seed was slightly lower or equal to the stover, hence a common thresher is not applicable to separate them easily and the second most important finding is that combine use of N and FYM captured more C seasonally than the fertilizer N alone, while fertilizer N has more manufacturing C foot print than the manure. Hence, integrated use of N and FYM has multi-faced benefits for reducing C foot print of input, captures more C during a season easily accessibility to the farmers, improves the crop yield and soil properties.