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Substantial initiatives are occurring in developing countries to integrate forage crops into crop-livestock systems to improve farmer livelihoods and reduce soil erosion. In particular, government authorities in western China focus on improving farmer livestock profits through greater forage crop production. We examined the whole-farm profit, downside risk, labour-use efficiency and feed balance effects of forage crop intensification on two simulated crop-livestock farm types in western China. Our methodology combined crop and livestock simulation modelling with whole-farm stochastic budgeting to capture both price and climate variability. We modelled the whole-farm effects of (1) introducing either forage vetch (Vicia sativa), forage oats (Avena sativa), or grain soybean (Glycine max) into current wheat (Triticum aestivum)-maize (Zea mays) systems and (2) replacing maize in current wheat-maize systems with either forage wheat, forage maize, or forage soybean. System intensification through incorporating a forage crop into current grain-cropping systems can increase average simulated profits without increasing downside risk on the simulated farms. As opposed to adding a forage crop into current grain-cropping systems, replacing a grain crop with a forage crop in current grain-cropping systems had a negative effect on profits, downside risk, and labour-use efficiency. Trade-offs existed between labour-use efficiency and profit as forage intensification increased labour demands. These effects were context specific, with greater positive profit effects of forage intensification for the higher-rainfall farm type. Overall, forage intensification in these systems benefited the households, but adoption will depend on household preferences and local agro-ecological and market factors. We demonstrated the importance of exploring proposed intensification options across different locations to capture impacts across diverse contexts. Providing these context-specific insights and exploring trade-offs within systems can help better understand livelihood improvement pathways. In locations with strong competing uses for labour, developing labour-saving practices appears critical. [ABSTRACT FROM AUTHOR]

Abstract: Simulation models can help to identify the whole-farm economic and biophysical impacts of smallholder farmers altering their farming systems. Incorporating long-term climate-induced variability in crop and livestock production enables the implications for agricultural household income and risk to be explored over a range of seasonal conditions. In this study, a simulation model is used to answer the following question: can reducing the area used for grain production by allocating more land to lucerne (Medicago sativa) and increasing livestock numbers improve total net farm income, reduce income variability and maintain grain self-sufficiency for farmers in the Qingyang Prefecture of Gansu Province, China? This was examined for three representative farm types found in the region: a low land-labour ratio farm household, a subsistence-oriented farm household, and a livestock-focused farm household. The Integrated Analysis Tool (IAT), a simulation model of a household farming system, was used to combine crop and forage production simulations, a livestock production model and a household socio-economic model to explore the impact of changes to farming systems over a 40year simulation period. Data from 90 surveyed households were used to define the structure of the three farm household types and to calibrate the IAT model specifically for Qingyang Prefecture. Additional livestock increased total household net incomes, increased net livestock incomes and reduced net crop incomes for the subsistence-oriented and livestock-focused farm households. For these households, the greater commitment to livestock also reduced grain self-sufficiency due to increased frequency of purchasing grain for home-consumption. Nevertheless, additional livestock reduced income variability for these households whilst improving total net income. The methodology used is useful for understanding changes in farming systems as it focuses on the feasibility and profitability of alternative enterprise mixes and incorporates climate variability. The results support current debates on targeting livestock policies towards smallholders as subsistence-oriented farm households appear to be the largest beneficiaries from livestock interventions. The analysis demonstrates that tradeoffs between net income and grain self-sufficiency are important for households, especially when they are moving from subsistence-based to market-based production. [Copyright &y& Elsevier]

• Effect of sowing date on biomass partition varied with forage crop species. • Aboveground biomass at flowering was dependent on rainfall and solar radiation. • Aboveground biomass at maturity more reliant on temperature and rainfall. • Allometric approach should be used in the analysis of allocation pattern. Biomass production and partitioning are important for crop production and is influenced by environmental conditions. Sowing date can profoundly influence biomass production and portioning in crop plants depending upon the local climatic conditions. However, the accumulation of biomass in different plant components in annual forages in response to changes in sowing date has not been quantified, especially for semiarid farming systems. A field experiment was conducted during 2011–2013 to investigate how sowing date (early, mid, late) influences biomass partitioning and the interrelationships with environments in four warm-season annual crops in the Loess Plateau of China. The aboveground biomass of all four crops was more reliant on rainfall and solar radiation at flowering and temperature and rainfall at maturity. Solar radiation, rainfall, and temperature had a combined effect on belowground biomass (0–0.3 m), depending on the forage crop. Reductions in biomass in the late-sown treatment were mostly attributed to plant size; the 'allometry' among plant components did not change. The changes of shoot: root and leaf: stem ratios were related to the relationship between biomass accumulation and rainfall, temperature and intercepted radiation. It is evident that dry matter allocation patterns in crops must be analyzed using a dynamic approach (allometry) and relate with environmental conditions, rather than a static approach using ratios. The results from this study provide references for crop management in forage production and breeding in semiarid areas. [ABSTRACT FROM AUTHOR]