Sustainability Of Organic Systems Research Articles

Sustainability evaluation of Sicily's lemon and orange production: An energy, economic and environmental analysis

The island of Sicily has a long standing tradition in citrus growing. We evaluated the sustainability of orange and lemon orchards, under organic and conventional farming, using an energy, environmental and economic analysis of the whole production cycle by using a life cycle assessment approach. These orchard systems differ only in terms of a few of the inputs used and the duration of the various agricultural operations. The quantity of energy consumption in the production cycle was calculated by multiplying the quantity of inputs used by the energy conversion factors drawn from the literature. The production costs were calculated considering all internal costs, including equipment, materials, wages, and costs of working capital. The performance of the two systems (organic and conventional), was compared over a period of fifty years. The results, based on unit surface area (ha) production, prove the stronger sustainability of the organic over the conventional system, both in terms of energy consumption and environmental impact, especially for lemons. The sustainability of organic systems is mainly due to the use of environmentally friendly crop inputs (fertilizers, not use of synthetic products, etc.). In terms of production costs, the conventional management systems were more expensive, and both systems were heavily influenced by wages. In terms of kg of final product, the organic production system showed better environmental and energy performances.

A Field Pea Ideotype for Organic Systems of Northern Italy

Field pea can provide protein-rich feed and improve the sustainability of organic systems, but its use is limited because of its poor competitiveness against weeds. This study assessed the value of an index of variety suitability for organic systems of northern Italy. The index was computed as the average variety rank for the following traits evaluated under conventional, weed-free conditions across two autumn sowings (early; late): (i) grain yield; (ii) straw yield; (iii) plant height at the onset of flowering; (iv) tolerance to lodging; (v) tolerance to ascochyta blight; (vi) winter survival; and (vii) earliness of maturity. Attika, which ranked first for index value (seventh for grain yield) across sowings among 50 recent European and Australian varieties, was compared with Metaxa (a recent variety marketed in EU for organic farming, eleventh for index value) for grain yield and competitiveness against weeds in a farmer-managed organic system across two years. Sowing time (autumn or late-winter) was also considered, adopting a factorial design with three replicates. Compared with late-winter sowing, autumn sowing led to higher yields (+56%), greater crop biomass and better ability to control weeds from late vegetative stages onwards. Attika out yielded Metaxa across (+17%) and within sowing times and tended to have greater competitive ability (28% lower weed biomass in April) and crop biomass. The optimal technique (Attika + autumn sowing) tested under organic and conventional farming at the same site in one year could reduce substantially the yield disadvantage of organic cropping. The index, possibly region-specific in its definition, may be used for recommendation or selection of material adapted to organic or low-input systems.

A review of farm‐scale nutrient budgets for organic farms as a tool for management of soil fertility

Abstract. On organic farms, where the importation of materials to build/maintain soil fertility is restricted, it is important that a balance between inputs and outputs of nutrients is achieved to ensure both short‐term productivity and long‐term sustainability. This paper considers different approaches to nutrient budgeting on organic farms and evaluates the sources of bias in the measurements and/or estimates of the nutrient inputs and outputs. The paper collates 88 nutrient budgets compiled at the farm scale in nine temperate countries. All the nitrogen (N) budgets showed an N surplus (average 83.2 kg N ha–1 yr–1). The efficiency of N use, defined as outputs/inputs, was highest (0.9) and lowest (0.2) in arable and beef systems respectively. The phosphorus (P) and potassium (K) budgets showed both surpluses and deficits (average 3.6 kg P ha–1 yr–1, 14.2 kg K ha–1 yr–1) with horticultural systems showing large surpluses resulting from purchased manure. The estimation of N fixation and quantities of nutrients in purchased manures may introduce significant errors in nutrient budgets. Overall, the data illustrate the diversity of management systems in place on organic farms, and suggest that used together with soil analysis, nutrient budgets are a useful tool for improving the long‐term sustainability of organic systems.