Do organic inputs matter – a meta-analysis of additional yield effects for arable crops in Europe

Abstract

Background and aims Organic inputs have a positive effect on the soil organic matter balance. They are therefore an important asset for soil fertility and crop growth. This study quantifies the additional yield effect due to organic inputs for arable crops in Europe when macronutrients are not a limiting factor. Methods A meta-analysis was performed using data from 20 long-term experiments in Europe. Maxima of yield response curves to nitrogen were compared, with and without organic inputs, under abundant P and K supply. Results We were surprised to find that, across all experiments, the mean additional yield effect of organic inputs was not significant (+ 1.4 % ± 1.6 (95 % confidence interval)). In specific cases however, especially for root and tuber crops, spring sown cereals, or for very sandy soils or wet climates, organic inputs did increase attainable yields. A significant correlation was found between increase in attainable yields and increase in soil organic matter content. Conclusions Aggregating data from 20 long-term experiments in Europe, this study shows that organic inputs and/ or soil organic matter do not necessarily increase yields, given sufficient nutrients are supplied by mineral fertilisers. Results show the relevance of some environmental factors for additional yield effect of organic inputs, but no simple relation between organic inputs and crop growth.

Straw incorporation increases crop yield and soil organic carbon sequestration but varies under different natural conditions and farming practices in China: a system analysis

“…4). This observation agrees with the study of Hijbeek et al (2017), who found that maize benefits significantly from organic inputs than those of wheat or barley. The most likely reason for this difference was that, compared to wheat, maize is mostly grown 10 require with higher temperature and precipitation (Tan et al, 2017), and these conditions favor a fasten straw decomposition and also result in a more rapid and abundant nutrient release (Hartmann et al, 2014;Ladha et al, 2011).…”

European long‐term field experiments: knowledge gained about alternative management practices

“…The effects of crop residue incorporation on soil chemical, physical and biological quality were mainly positive, and agree with the previous literature (Hijbeek et al . (). As reported in Lehtinen et al .…”

“…Hijbeek et al . () selected 20 LTEs, of which some were from the same database, to investigate the additional value of organic amendments when macronutrients were applied in sufficient amounts. They found a significant correlation between increases in soil organic matter contents and increases in crop yields; however, the mean additional yield effect of organic amendments remained insignificant.…”

Major limitations to achieving “4 per 1000” increases in soil organic carbon stock in temperate regions: Evidence from long‐term experiments at Rothamsted Research, United Kingdom

“…In the sandy loam at Woburn, modelling with RothC‐26.3, showed that 5%, at most, of the C added in plant residues over a 70‐year period is still present in the soil (Johnston et al., ) but, again, this caused measurable changes in soil properties. However, improvements in soil physical properties caused by increased SOC do not necessarily translate into consistently increased crop yields (Hijbeek et al., ).…”