Bioactive carbon improves nitrogen fertiliser efficiency and ecological sustainability

Peter Espie,Haley Ridgway

doi:10.1038/s41598-020-60024-3

Abstract

Agriculture’s most pressing challenge is raising global food production while minimising environmental degradation. Nutrient deficiencies, principally nitrogen (N), limit production requiring future increases in fertiliser use and risk to proximal non-agricultural ecosystems. We investigated combining humate with urea, globally the most widely used N-suppling fertiliser, in a four-year field study. Humate increased pasture yield by 9.8% more than urea and significantly altered soil microbial diversity and function. Humate increased N retention suggesting microbial sequestration may lower N leaching and volatilisation losses. Humic microbial bio-stimulation could feasibly increase fertiliser efficiency and development of ecologically sustainable agriculture.

Highlights

Agriculture’s most pressing challenge is raising global food production while minimising environmental degradation
In the first growing season (2014–15) urea increased average production by 47% compared with nil fertiliser application in unfertilised grassland, urea with 10% humate by 70%, urea with 20% humate by 59% and urea with 10% humate and gauno by 42% (F = 13.4, P < 0.001, Fig. 1b)
Ten percent humate addition gave the greatest rate response while 20% gave a slightly lower non-significant response, possibly indicating a small inhibitory rate effect or this may be due to experimental variability

Summary

Introduction

Agriculture’s most pressing challenge is raising global food production while minimising environmental degradation. Principally nitrogen (N), limit production requiring future increases in fertiliser use and risk to proximal non-agricultural ecosystems. Humic microbial bio-stimulation could feasibly increase fertiliser efficiency and development of ecologically sustainable agriculture. It is estimated one billion people currently suffer from chronic hunger and that global food production needs to double when the global population will stabilise at around 9.8 billion in 20501,2. Raising global food production will unavoidably require increases in fertiliser inputs, principally nitrogen (N) and phosphorus (P)[12,13]. The required increase in global agricultural fertiliser is forecast to cause 2.4- to 2.7-fold increases in nitrogen- and phosphorus-driven eutrophication of terrestrial, freshwater, and near-shore marine ecosystems, with significant loss of ecosystem services[19]. Recent studies have shown how closely microbial diversity and function are coupled with plant productivity via root exudates, nutrient cycling and uptake, plant growth processes and climate change[24,25,26]

Methods

Results

Conclusion