Lablab Purpureus Influences Soil Fertility and Microbial Diversity in a Tropical Maize-Based No-Tillage System

Patricia Dörr De Quadros,Roberta Fulthorpe,Raquel Dias,Flávio A De O Camargo,Adriana Giongo,Kateryna Zhalnina,Eric W Triplett,Adam R Martin,Cimelio Bayer

doi:10.3390/soilsystems3030050

Abstract

There are multiple mechanisms by which enhanced diversity of plant communities improves soil structure and function. One critical pathway mediating this relationship is through changes to soil prokaryotic communities. Here, nine different cropping systems were studied to evaluate how legume and grass cover crops influence soil fertility and microbial communities in a maize-based no tillage system. The soil’s bacterial and archaeal communities were sequenced (Illumina GAIIx, 12 replicates for treatment) and correlated with eight different soil features. The microbial community composition differed widely between planting treatments, with three primary “community types” emerging in multivariate space: (1) A community type associated with bare soil linked with low P, low pH, and high aluminum [Al]; (2) a community type associated with Lablab beans linked with high soil N, total organic carbon and other base cation concentrations, and high pH; and (3) a community type of all other non-lablab planting arrangements linked with higher soil P (relative to bare soil), but lower soil fertility (N and base cations). Lablab-based arrangements also expressed the highest microbial richness and alpha diversity. The inclusion of Lablab in maize-based cropping systems represents a potential alternative to reduce the use of chemical fertilizers and increase the chemical and biological quality in agricultural soils under the no-tillage system.

Highlights

Management strategies that reduce chemical fertilizer use and increase soil quality in agricultural systems are essential for sustainable agricultural systems
15.3 mg N·kg−1 ) cropping systems were 8-fold higher than in the bare soil (1.8 mg N·kg−1 ); the same treatments presented twice the total N when compared with the bare soil
While the highest observed pH (5.5) was detected in the soil planted with the pangola pasture, the lowest pH (4.6) was detected in the soil under the pigeon pea+maize intercropping system

Summary

Introduction

Management strategies that reduce chemical fertilizer use and increase soil quality in agricultural systems are essential for sustainable agricultural systems. This is true for the world’s most commonly planted crops, including soy, wheat, maize, and rice, which as of 2014 cumulatively occupied nearly 50% of the world’s ~1.38 billion ha of agricultural lands [1]. No-tillage systems naturally increase the soil organic carbon and N levels, but the addition of legume cover crops can further increase natural inputs of N and other nutrients, reducing the need for expensive chemical fertilizers [2,3].

Methods

Results

Conclusion