Nitrogen Immobilisation and Microbial Biomass Build-Up Induced by Miscanthus x giganteus L. Based Fertilisers

Michael Stotter,Florian Wichern,Ralf Pude,Martin Hamer

doi:10.3390/agronomy11071386

Abstract

Cultivation of Miscanthus x giganteus L. (Mis) with annual harvest of biomass could provide an additional C source for farmers. To test the potential of Mis-C for immobilizing inorganic N from slurry or manure and as a C source for soil organic matter build-up in comparison to wheat (Triticum aestivum L.) straw (WS), a greenhouse experiment was performed. Pot experiments with ryegrass (Lolium perenne L.) were set up to investigate the N dynamics of two organic fertilisers based on Mis at Campus Klein-Altendorf, Germany. The two fertilisers, a mixture of cattle slurry and Mis as well as cattle manure from Mis-bedding material resulted in a slightly higher N immobilisation. Especially at the 1st and 2nd harvest, they were partly significantly different compared with the WS treatments. The fertilisers based on Mis resulted in a slightly higher microbial biomass C and microbial biomass N and thus can be identified as an additional C source to prevent nitrogen losses and for the build-up of soil organic matter (SOM) in the long-term.

Highlights

Technological developments, as well as economic conditions, have reduced the production costs in agriculture in the last decades
The cumulated N uptake of ryegrass was significantly lower (7% to 24%) compared toThpeurceuCmSuwlahteend MNisuoprtaWkSe woferreyemgirxaesds wwiaths CsiSgnainfdicathnetnlyalpopwlieedr (a7s%C-troic2h4o%rg) acnoimc Npared to pfuerretilCisSerw(Thaebnle M7).isCoomr WpaSredwteorepumreixCeSdfewrtiitlhisaCtiSona,ntdhetahdednitaiopnpolifeWd SastoCC-Sriicnhduocregdanaic N ferti7li%setro(1T7a%blreed7u).ctCioonminpaprlaendt tNo upputraekeCaSnfderthtieliasdadtiiotino,nthofeMadisdinitdiounceodfaWslSigthotlyCsStrionndguecred a 7% troed1u7c%tiornedwuicthtiopnlanint NplaunpttaNkeubpetiankgereadnudcethdebayd1d2%itioton2o4f%M(Tisabinled7u).ced a slightly stronger reduction with plant N uptake being reduced by 12% to 24% (Table 7)
At the 2nd and 3rd harvest, N uptake of ryegrass, fertilized with mixtures of Miscanthus x giganteus L. (Mis) or Wheat Straw (WS) and Cattle Slurry (CS) slightly increased and the N uptake of ryegrass fertilized with pure CS slightly decreased, compared to the 1st harvest, only to a small extent (Figure 1)

Summary

Introduction

Technological developments, as well as economic conditions (agricultural subsidies, world market trade), have reduced the production costs in agriculture in the last decades. This has changed production methods resulting in nutrient access and pollution of the environment, especially in areas with high livestock density and slurry application and that, threaten the long-term stability of agricultural production [1,2]. It is essential to use organic fertilisers and other C sources in a way that retains N and C in the crop-livestock-soil system and stops further SOC reduction or promotes SOC build-up. Thereby, soil microorganisms have a key function because they regulate essential C and N turnover processes in the soil

Methods

Results

Discussion

Conclusion