Optimization of the environmental performance of rainfed durum wheat by adjusting the management practices

Abstract

Altering agricultural practices to meet the sustainability criteria can be a promising solution for reducing environmental burdens related to intensive agricultural management practices. In this study, different wheat management practices are proposed and evaluated for their environmental performances from a life cycle prospective. Information on crop yield response to nitrogen (N) fertilizer rates and soil disturbance was collected from field experiments conducted during the growing season (2010–2012) at Pantanelli experimental farm in southern Italy. Environmental impacts are organized in impact categories, which are estimated under the proposed scenarios using different methodology. All impacts are linked to the production of 1 kg of durum wheat using farm gate as a system boundary. Results showed that for all the examined scenarios, largest burdens are related to the production of farm inputs, while the lowest to cultivation face, except for no nitrogen supply scenarios. Impact assessment results at midpoint level indicate that most impact categories have a direct correlation between impact assessment values, which are very much linked to grain productivity, and management intensity with some exceptions. In most cases, T1 performed better than other scenarios whereas T8 reported the highest impact. At damage category, however, most of the impacts on human health came from Climate change (49.4%) and Particulate matter formation (49.5%). For the damage to ecosystems, minor differences between the different production scenarios were calculated with best option was for the lowest input scenario (T1). Only two impact categories contributed in a clear manner to the total impact on ecosystem. Climate change and Agricultural land occupation represent the majority of the total impacts on ecosystem with 50.5% and 46.3%, respectively. Impact assessment for the damage category “Resources” show that the majority of the impacts came from the depletion of fossil fuel. The use of diesel fuel in tractors for the various agricultural steps was a significant process that was responsible for the impact on the proposed scenarios. Comparative analysis for the proposed management scenarios give the possibility for the optimization of farming systems, which resulted in increasing productivity with minimum input. This has led to the reduction of impacts resulted from the production of 1 kg of product. It was found that the contribution of conservation agriculture technique (NT with low input of N fertilizer) to the impact categories and GWP index was small compared to that of CT and RT. Data obtained from this study could help farmers as well as the industry to focus on the most emission-intensive stages of durum wheat production in order to reduce impacts by improving productivity.