. In this forum paper we discuss how soil scientists can help to reach the recently adopted UN Sustainable Development Goals (SDGs) in the most effective manner. Soil science, as a land-related discipline, has important links to several of the SDGs, which are demonstrated through the functions of soils and the ecosystem services that are linked to those functions (see graphical abstract in the Supplement). We explore and discuss how soil scientists can rise to the challenge both internally, in terms of our procedures and practices, and externally, in terms of our relations with colleague scientists in other disciplines, diverse groups of stakeholders and the policy arena. To meet these goals we recommend the following steps to be taken by the soil science community as a whole: (i) embrace the UN SDGs, as they provide a platform that allows soil science to demonstrate its relevance for realizing a sustainable society by 2030; (ii) show the specific value of soil science: research should explicitly show how using modern soil information can improve the results of inter- and transdisciplinary studies on SDGs related to food security, water scarcity, climate change, biodiversity loss and health threats; (iii) take leadership in overarching system analysis of ecosystems, as soils and soil scientists have an integrated nature and this places soil scientists in a unique position; (iii) raise awareness of soil organic matter as a key attribute of soils to illustrate its importance for soil functions and ecosystem services; (iv) improve the transfer of knowledge through knowledge brokers with a soil background; (v) start at the basis: educational programmes are needed at all levels, starting in primary schools, and emphasizing practical, down-to-earth examples; (vi) facilitate communication with the policy arena by framing research in terms that resonate with politicians in terms of the policy cycle or by considering drivers, pressures and responses affecting impacts of land use change; and finally (vii) all this is only possible if researchers, with soil scientists in the front lines, look over the hedge towards other disciplines, to the world at large and to the policy arena, reaching over to listen first, as a basis for genuine collaboration.

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The significance of soils and soil science towards realization of the United Nations sustainable development goals

The significance of soils and soil science towards realization of the United Nations Sustainable Development Goals

Crop residue management and soil health: A systems analysis

Global support for Conservation Agriculture (CA) as a pathway to Sustainable Intensification is strong CA revolves around three principles: no-till (or minimal soil disturbance), soil cover, and crop rotation The benefits arising from the ease of crop management, energy/cost/time savings, and soil and water conservation led to widespread adoption of CA, particularly on large farms in the Americas and Australia, where farmers harness the tools of modern science: highly-sophisticated machines, potent agrochemicals, and biotechnology Over the past 10 years CA has been promoted among smallholder farmers in the (sub-) tropics, often with disappointing results Growing evidence challenges the claims that CA increases crop yields and builds-up soil carbon although increased stability of crop yields in dry climates is evident Our analyses suggest pragmatic adoption on larger mechanized farms, and limited uptake of CA by smallholder farmers in developing countries We propose a rigorous, context-sensitive approach based on Systems Agronomy to analyze and explore sustainable intensification options, including the potential of CA There is an urgent need to move beyond dogma and prescriptive approaches to provide soil and crop management options for farmers to enable the Sustainable Intensification of agriculture

/pdf/beyond-conservation-agriculture-1407c2148e.pdf

Beyond conservation agriculture

Understanding the impact and adoption of conservation agriculture in Africa: A multi-scale analysis

Trade-offs around the use of biomass for livestock feed and soil cover in dairy farms in the Alaotra lake region of Madagascar

Family farming in the tropics suffers from low crop productivity mainly due to a combination of poor soil fertility, low investment capacity, and a variable climate. The Lake Alaotra region of Madagascar is no exception and rainfed production is particularly hard hit. To evaluate the agronomic benefits of conservation agriculture (CA) in a region of erratic rainfall, we analysed four years of yield, management and climatic data from 3803 upland rice fields cultivated by farmers and monitored by researchers. Fields located on rainfed lowlands and hillsides were cultivated with sole rice using conventional tillage (Cv) or rice sown with no-tillage on dead organic mulch and rotated with other cereal/legume combinations (CA) from 2006 to 2011. A first global comparison across seasons, locations and years of adoption showed significantly higher average yields under CA, with no change in variance (on lowland: 2.6 ± 0.9 t ha–1 Cv, 2.8 ± 0.9 t ha–1 CA; on hillside: 2.1 ± 0.8 t ha–1 Cv, 2.4 ± 0.8 t ha–1 CA). Grouping fields according to the number of years under CA (first to fourth) revealed that CA gradually increased average yields and reduced the coefficient of variation in the short and mid-term (on lowland: +0.2 t ha–1 and –6% coefficient of variation; on hillside: +0.7 t ha–1 and –13% coefficient of variation, over four to six years of successive CA cropping). The average yield increase under CA was not associated with an increase in mineral fertiliser use, as farmers used the same amounts of fertilisers (or none) under Cv and CA. The comparison Cv versus CA also highlighted a major benefit of CA regarding climate: it widened the window of possible sowing dates. A classification and regression tree analysis of the entire dataset revealed that rice yield was more affected by agro-environmental factors than management factors (fertilisation, Cv or CA), and extreme climate variability such as the severe drought of 2007–2008 could not be offset by CA. The hypothesis of yield penalties during the first years of implementation of CA cannot be verified with the evidence presented in this study.

Short- to mid-term impact of conservation agriculture on yield variability of upland rice: evidence from farmer's fields in Madagascar

Can conservation agriculture improve crop water availability in an erratic tropical climate producing water stress? A simple model applied to upland rice in Madagascar

Conservation agriculture in Africa: Analysing and foreseeing its impact - Comprehending its adoption : Final case study report (D1.6)

En Afrique sub-saharienne (ASS), l’agriculture de conservation (AC) est diffusee afin de d’ameliorer durablement la productivite de l’agriculture familiale. Cette AC est basee sur les principes de travail reduit du sol, d’une couverture permanente et de rotations introduisant des legumineuse. Parmi tous les benefices potentiels de l’AC, le mulch peut ameliorer le bilan hydrique et tamponner le stress hydrique, et donc securiser les rendements, lorsque les pluies sont limitees et/ou aleatoirement distribuees. A Madagascar, la region du lac Alaotra connait une forte expansion de la riziculture pluviale. Etant caracterisee par une distribution des pluies tres erratique, la pratique de l’AC semble pertinente pour securiser la production pluviale. L’objectif de cette etude est donc d’evaluer dans quelle mesure cet alea climatique est tamponne par l’AC. Tout d’abord, a travers revue de la litterature scientifique, nous avons ouvert a une problematique plus large. En effet, au regard des projections de croissance demographique et de changement climatique (CC) en ASS, l’AC est proposee comme solution ‘climate-smart’ ; i.e. une agriculture capable d’augmenter la productivite et de s’adapter au CC tout en l’attenuant. Les etudes identifiees en ASS montrent une capacite de l’AC a augmenter les rendements sur le long-terme, et a plus court-terme dans les contextes climatiques ou les pluies sont faibles et/ou mal distribuees. Cela suggere donc une capacite de l’AC a s’adapter au CC qui prevoit une augmentation de la variabilite de la distribution des pluies en ASS. La capacite de l’AC a attenuer le CC en sequestrant du carbone (C) dans les sols reste en suspens car le stockage du C se fait principalement en surface et la stabilite de ce C est questionnee. Nous nous sommes ensuite recentres sur le sujet et la zone de cette etude afin d’evaluer le potentiel de l’AC a tamponner l’alea pluviometrique. En se basant sur les donnees de suivi de parcelles en transition vers l’AC sur quatre saisons contrastees, nous avons constate une augmentation des rendements moyens en riz pluvial des la premiere annee de pratique, avec une augmentation progressive des rendements et une diminution de la variabilite. Les donnees ont egalement suggere une securisation des semis precoces et tardifs en AC. Nous avons constate un poids important du climat sur la variabilite des rendements dans la zone d’etude. Cette analyse exploratoire nous a donc permis d’observer des effets positifs de l’AC dans le contexte climatique du lac Alaotra, suggerant notamment un effet potentiel sur la ressource hydrique. Mais les informations a notre disposition ne nous ont pas permis de verifier cette hypothese. Nous nous sommes donc interesses a l’impact du mulch sur le bilan hydrique et les rendements en riz pluvial dans les conditions agro-climatiques de la zone d’etude. Nous avons effectue une experimentation virtuelle, en utilisant le modele PYE-CA. Nous avons confirme la capacite du mulch a reduire le ruissellement. Nous avons identifie les dates de semis pour lesquelles le riz pluvial est le moins impacte par le stress hydrique dans la region. Les resultats nous ont indique que pour les dates de semis majoritairement pratiquees par les agriculteurs, et dans un eventail de conditions de sol, la disponibilite en eau est tres peu affectee par une modification du ruissellement. Les benefices d’une reduction du ruissellement apparaissent dans des conditions hydriques plus stressantes telles que des dates de semis precoce ou une intensification, en diminuant la variabilite des rendements. Cette etude nous a permis de mieux apprehender les impacts de l’AC sur le bilan hydrique dans le contexte climatique de notre zone d’etude. Pour faire sens, ces resultats sont a integrer a l’echelle exploitation, voire plus large, pour identifier les contraintes et avantages induits par les systemes en AC dans le contexte socio-economique du lac Alaotra.

Pertinence de l'agriculture de conservation pour tamponner les aléas climatiques : cas des systèmes de culture en riz pluvial au Lac Alaotra, Madagascar

Guillaume Bruelle

Papers

Trade-offs around the use of biomass for livestock feed and soil cover in dairy farms in the Alaotra lake region of Madagascar

Short- to mid-term impact of conservation agriculture on yield variability of upland rice: evidence from farmer's fields in Madagascar

Can conservation agriculture improve crop water availability in an erratic tropical climate producing water stress? A simple model applied to upland rice in Madagascar

Conservation agriculture in Africa: Analysing and foreseeing its impact - Comprehending its adoption : Final case study report (D1.6)

Pertinence de l'agriculture de conservation pour tamponner les aléas climatiques : cas des systèmes de culture en riz pluvial au Lac Alaotra, Madagascar