Soil biota enhance agricultural sustainability by improving crop yield, nutrient uptake and reducing nitrogen leaching losses

Abstract

Summary1. Efficient resource use is a key factor for sustainable production and a necessity for meeting future global food demands. However, the factors that control resource use efficiency in agro-ecosystems are only partly understood. 2. We investigated the influence of soil biota on nutrient leaching, nutrient-use efficiency and plant performance in outdoor, open-top lysimeters comprising a volume of 230 L. The lysimeters were filled with sterilized soil in two horizons and inoculated with a reduced soil-life inoculum (soil biota ≤11 lm, microbially dominated) and an enriched soil-life inoculum [soil organisms ≤2 mm, also containing arbuscular mycorrhizal fungi (AMF)]. A crop rotation was planted, and nutrient leaching losses, plant biomass and nutrient contents were assessed over a period of almost 2 years. 3. In the first year of the experiment, enriched soil life increased crop yield (+22%), N uptake (+29%) and P uptake (+110%) of maize and strongly reduced leaching losses of N (À51%, corresponding to a reduction of 76 kg N ha À1 ). In the second year, wheat biomass (+17%) and P contents (+80%) were significantly increased by enriched soil life, but the differences were lower than in the first year. 4. Enriched soil life also increased P mobilization from soil (+112%) and significantly reduced relative P leaching losses (À25%), defined as g P leached per kg P plant uptake, as well as relative N leaching losses (À36%), defined as kg N leached per kg N plant uptake, demonstrating that nutrient-use efficiency was increased in the enriched soil-life treatment. 5. Synthesis and applications. Soil biota are a key factor determining resource efficiency in agriculture. The results suggest that applying farming practices, which favour a rich and abundant soil life (e.g. reduced tillage, organic farming, crop rotation), can reduce environmental impacts, enhance crop yield and result in a more sustainable agricultural system. However, this needs to be confirmed in field situations. Enhanced nutrient-use efficiency obtained through farming practices which exert positive effects on soil biota could result in reduced amounts of fertilisers needed for agricultural production and reduced nutrient losses to the environment, providing benefits of such practices beyond positive effects on biodiversity.

Effect of cover crops on physico-chemical attributes of soil in a short-term experiment in the southwestern Amazon region

“…Lower soil penetration resistance was detected in the 0 to 5 cm layer and may be related to higher microbial activity in this region (Bender and Van Der Heijden, 2015). There was no difference in the 30 to 40 cm zone.…”

“…Cover crops keep the soil surface continuously covered by straw, recycling nutrients and making them available for successive crops via the gradual decomposition of the organic residues (Bender and Van Der Heijden, 2015). However, the perception of the use of straw by farmers can be very negative due the cost of implementation and the lack of information about the economic returns on the investment (Cerdà et al, 2017).…”

The practice of sustainability in response to the challenges of agriculture in Mexico

“…They also help restore the balance of minerals and organic matter of soils and allow the use of raw materials from crop residues and underused local resources, such as manure, minerals, herbs and/or natural repellents (garlic, onion, chili, etc.) with the consequent reduction of costs [11,20,29,40]. In addition, control of production processes is given to local producers creating employment in the communities, increasing their self-sufficiency and their ability to adapt to changes [9,18].…”

“…The latter is more relevant considering the great difficulties of making compatible the feeding needs of a growing population with the urgency of mitigating impacts to the environment, where the adapting capacity must be strengthened within a context of socioeconomic crisis and climate change [9,10,[20][21][22][23].…”

“…The environment in the region would be favored with reduced agriculture impacts, improved water quality and increased soil microbiota and minerals. The latter is of major importance for the serious problems of soil nitrification and filtration of chemicals to aquifers in the region due to cropping activities [11,20].…”