Enhancing the application of organic fertilisers by members of agricultural cooperatives.

Scientific literature has reported that participation in agricultural cooperatives has positive effects on small farmers' preference for organic fertilisers over chemical fertilisers. However, there is limited focus on enhancing the voluntary use of organic fertilisers by small farmers who have joined an agricultural cooperative. This paper describes an agent-based model for simulating small farmers' decision-making with regard to fertiliser selection. Ninety six farmers (members) of one of the largest strawberry production cooperatives in China were assessed to understand their willingness to use different fertilisers and their socioeconomic characteristics. Simulation results showed that for farmers belonging to the agricultural cooperative who earn higher marginal profits, variations in the prices of the agricultural produce had no significant effect on their behaviour in terms of the use of organic fertilisers. The number of farmers using organic fertilisers at the beginning of the first year has a positive relationship with the increase in the rate at which farmers use organic fertilisers. However, the count does not alter the final number of farmers who use organic fertilisers after several years. Moreover, farmers' willingness to use organic fertilisers enhances the increasing speed and final number of farmers using organic fertilisers simultaneously. The design of strategies (increasing the number of farmers using organic fertilisers at the beginning of the first year and enhancing farmers' willingness to use organic fertilisers) has a significant effect on the promotion of organic fertiliser application by agricultural cooperatives in China.

Phenotyping field-state wheat root system architecture for root foraging traits in response to environment×management interactions.

An important aspect of below-ground crop physiology is its root foraging performance, which is inherently related to root system architecture (RSA). A 2-yr field experiment was conducted and the field-state wheat RSA was phenotyped for root foraging trait (RFT). Four RSA-derived traits, i.e. Root horizontal angle (RHA), axial root expansion volume (AREV), RSA convex hull volume (CHV) and effective volume per unit root length (EVURL), were analyzed for RFTs in response to environment × management interactions. Results showed a dynamical RHA process but without statistical difference both within crop seasons and tillage treatments. AREV increased with root developmental stages, revealing an overall better root performance in the first year. However, tillage treatments did not induce observed difference within both crop seasons. CHV varied drastically from year to year and between tillage treatments, correlating well to the root length, but not with RHA. EVURL was both sensitive to tillage treatments and crop seasons, being a potential indicator for RFT. Above all, tillage effect on RFT was statistically far less than that induced by crop seasons. Pro/E assisted modeling can be used as an effective means for phenotyping integrated, RSA-derived, RFTs for root foraging response to induced environment × management interactions.

Phenotyping for the dynamics of field wheat root system architecture.

We investigated a method to quantify field-state wheat RSA in a phenotyping way, depicting the 3D topology of wheat RSA in 14d periods. The phenotyping procedure, proposed for understanding the spatio-temporal variations of root-soil interaction and the RSA dynamics in the field, is realized with a set of indices of mm scale precision, illustrating the gradients of both wheat root angle and elongation rate along soil depth, as well as the foraging potential along the side directions. The 70d was identified as the shifting point distinguishing the linear root length elongation from power-law development. Root vertical angle in the 40 mm surface soil layer was the largest, but steadily decreased along the soil depth. After 98d, larger root vertical angle appeared in the deep soil layers. PAC revealed a stable root foraging potential in the 0-70d period, which increased rapidly afterwards (70-112d). Root foraging potential, explained by MaxW/MaxD ratio, revealed an enhanced gravitropism in 14d period. No-till post-paddy wheat RLD decreased exponentially in both depth and circular directions, with 90% roots concentrated within the top 20 cm soil layer. RER along soil depth was either positive or negative, depending on specific soil layers and the sampling time.