Profitability and opportunity of conservation agriculture in acid savannah grasslands of Laos

Abstract

In north-eastern Laos, the savannah grasslands of the Plain of Jars cover vast areas of potentially cultivable land. However, soil acidity, low inherent fertility, and the absence of alternatives to tillage represent significant constraints to the development of sustainable smallholder agriculture. Our objective was to evaluate the potential for conservation agriculture (CA) to enhance soil productivity and farming system profitability. A three-year rotation of rice/maize/soybean was tested under three fertilization levels and four agricultural systems: one conventional tillage-based (CT) system and three CA systems based on no-tillage with cover crops. After four cropping seasons, our results show that, compared with CT, CA systems led to similar-to-higher grain production, similar-to-higher profits, higher opportunity of livestock system intensification, and higher labour productivity regardless of fertilization levels. While CA represents a relevant alternative to current practices, our results suggest that its contribution to the emergence of a sustainable smallholder agriculture is conditioned by broader institutional transformations, including the enrolment of local manufacturers and traders for deploying no-till implements and seed market channels for cover crops, long-term public support to maintain active research and technical mentoring to farmers, and possibly the integration of ecosystem services in agricultural policy. (Résumé d'auteur

Dynamics of adopting conservation agriculture in family farms: from technique to innovative process

“…Les effets de la suppression du labour et du contrôle de la levée des mauvaises herbes par le mulch de couverture sur la réduction des temps de travaux ont également été évalués dans ces expérimentations (Jat et al, 2014 ;Farooq et Siddique, 2015). L'intérêt agronomique de ces travaux est indéniable, mais leur extrapolation aux contextes d'action des paysans est limitée du fait de leur insertion presque exclusive dans des dispositifs expérimentaux « contrôlés » par la recherche, en station ou en parcelle paysanne, où l'approvisionnement en intrants et petits équipements et un conseil technique rapproché aux agriculteurs sont assurés par les chercheurs (Lienhard et al, 2014). La faisabilité de ces technologies par les petits agriculteurs dans leurs conditions habituelles de production soulève de nombreux problèmes pouvant réduire leur adoption et leurs performances, tels que l'absence de clôture fonctionnelle des champs pour protéger les mulchs des troupeaux, la faible disponibilité et le prix élevé des intrants sur les marchés locaux, ou l'accès limité aux matériels adaptés.…”

Impact of a conservation agriculture system on soil characteristics, rice yield, and root-parasitic nematodes in a Cambodian lowland rice field

“…The cover crops grown in between crop cycles provide a continuous flow of fresh organic matter increasing soil organic C and N concentrations (Hok et al, 2015;Sá et al, 2015;Patra et al, 2019) while they also enhance soil biodiversity (Lienhard et al, 2013a, b;Choudhary et al, 2018;Jiang et al, 2018). The effects of DMC on the abundance and diversity of soil microbial communities' benefit, in turn the plant's development, and thus yield (Hungria et al, 2009;Palm et al, 2014;Lienhard et al, 2014). Besides the micro-organisms, the relationships between DMC and the soil nematofauna have also been studied (Villenave et al, 2009;Ito, 2015;Ito et al, 2015).…”

Co-designing innovative cropping systems that match biophysical and socio-economic diversity: The DATE approach to Conservation Agriculture in Madagascar, Lao PDR and Cambodia

“…Farmers were interested in expanding their field crops (e.g. rice, maize and soybean) on these marginal soils and in improving pasture for cattle raising (Lienhard et al, 2013c).…”

“…with Brachiaria spp., to feed cattle, or with a mixture of finger millet and pigeon pea, to feed pigs. These systems should enable the intensification of livestock systems, which is a national priority to alleviate poverty (Lienhard et al, 2010, 2013c; Jullien et al, 2010b). The fodder crop is also considered to be an important stage in restoring soil fertility, such as in Xieng Khouang Province (Lao PDR), where Brachiaria was grown as fodder for livestock, at the same time preparing aluminum toxic soils for crop production.…”