Balancing rice and non-rice crops: Managing the risks from soil constraints in Mainland Southeast Asian rice systems

• Published in: Field crops research 2020-02, Vol.246, p.107677, Article 107677
• Main Authors: Vial, Leigh K., Molesworth, Anika, Lefroy, Rod D.B.
• Format: Article
• Language: English
• Subjects: Mainland Southeast Asia; Non-rice crops; Rice-based systems; Risk management; Soil constraints
• ISSN: 0378-4290; 1872-6852
• DOI: 10.1016/j.fcr.2019.107677

•Productive non-rice crops are a critical means of improving livelihoods in the rice systems of mainland Southeast Asia.•The soil constraints from puddling paddy soils, being a hardpan and degraded topsoil, pose risks to non-rice crop productivity.•A risk framework is proposed to improve productivity of non-rice crops in a rice system: tolerate, reduce or avoid the risks from soil constraints.•Hence, soil constraints can be tolerated, managed, ameliorated annually, reduced, or, avoided by growing only non-rice crops or only rice.•Hence, paddy fields are differentiated into five categories, to help choose land uses that improve non-rice crop productivity in a rice system. Non-rice crops (NRCs) are an increasingly important means of improving farmer livelihoods in rice-based farming systems in Mainland Southeast Asia (MSEA), but NRC productivity faces risks from the soil constraints that result from traditional wet rice cultivation, namely degraded topsoil, a sub-surface hardpan and consequent reduced available water-holding capacity (AWC). Farmers can address the risks to NRCs posed by these soil constraints in several ways: accept the risks by tolerating the soil constraints, reduce the risks by managing the constraints, ameliorating them seasonally or reducing them by adopting dry soil preparation for rice, or avoid the risks by either ceasing rice production to eliminate the constraints or ceasing NRC production. The differentiation of fields into five consequent management regimes – wet preparation rice, wet preparation rice with management or amelioration of constraints, dry preparation rice, dedicated NRC-only fields, and dedicated rice-only fields – gives insight as to how both rice and NRC productivity can be balanced in a rice-based system, not just in an individual field. This paper outlines a framework for more optimal rice and NRC production, highlights the information and further research required to improve on-farm decision-making, and suggests how this framework can be applied in practice.