Pruning Residues as an Alternative to Traditional Tillage to Reduce Erosion and Pollutant Dispersion in Olive Groves

Abstract

During the seasons 2003/04, 2004/05 and 2005/06, a study was made of the evolution of runoff as well as soil and available P and K losses in the sediment carried away in a conventional till system-that most used at the present time-and in a no till system with added pruning remains in an olive grove of the picual variety located in Torredonjimeno (Jaén, Spain). A group of microplots for sediment collection in a randomized complete block design was established. The samples were collected in the field after each storm. In the study period, a total of 21 storms were recorded, with a precipitation of 450 mm in 2003/04, 179 mm in 2004/05 and 388 mm in 2005/06. The erosivity of the rainfall was characterized and the cover percentage in the plots throughout the time was determined. The establishment of pruning remains reduced soil loss with respect to conventional tillage (CT) in the 3 years (72%). Likewise, the available P loss greatly declined in the study (46.4%) under conservation agriculture. The reduction in available K loss (72.4%) was much greater than that of available P. The close relationship between both variables and sediment production also stands out. Runoff was the parameter on which the pruning remains had the least influence with only an 11% average reduction.

Long-Term Effects of Residue Management on Soil Fertility in Mediterranean Olive Grove: Simulating Carbon Sequestration with RothC Model

“…The residues left from fruit cleaning in the oil mill prior to extracting the oil, composed of leaves, green twigs, and superficial soil, can also be spread on the soil surface, returning to the soil the elements previously taken up by the tree. These new soil-management systems are an alternative for improving the soil quality and fertility in sustainable agricultural system (Ordóñez et al, 2001;Rodríguez-Lizana et al, 2008;Nieto et al, 2010). Many studies on agricultural ecosystems, as reviewed by Jarecki & Lal (2003), have documented the changes in soil properties when the soil management shifts from tillage to cover crop, mainly the increase of SOC and nitrogen (N).…”

“…The management of crop residues is an important aspect of conservation systems (Six et al, 1999;Paustian, 2000;Lal, 2008), since proper distribution on the ground surface reduces water losses and thus discourages soil erosion (Schomberg et al, 1999). Water and erosion constitute especially serious issues in zones that have a Mediterranean climate and can be only partially solved by recycling the crop debris (Rodríguez-Lizana et al, 2008).…”

“…The impact of different soil-management systems on soil properties have been studied for olive orchards (e.g. Hernández et al, 2005;Soria et al, 2005;Castro et al, 2008;Gómez et al, 2009) but only a few works have evaluated the effect of shredded olive-pruning debris (Ordóñez et al, 2001, Sofo et al, 2005Rodríguez-Lizana et al, 2008). Recently, agricultural soils have been identified as the major carbon pool in the context of its global cycle.…”

Estimation of soil coverage of chopped pruning residues in olive orchards by image analysis

“…As in other Mediterranean zones, the incidence of soil loss is notably high in southern Spain because approximately 1/3 of crops are grown on slopes with inclines greater than 15% (CAP, 2006). Olive growing, in particular, provides low soil coverage; approximately 75% of the soil surface is uncovered and exposed to erosion (Rodríguez-Lizana et al, 2008). Traditionally, olive growing has been characterized by high tillage, which increases erosion and soil loss through runoff.…”

“…It has also replaced the traditional practice of crop residue burning, which is now strictly controlled by authorities to avoid the high risk of fire and high quantities of CO 2 that are released into the atmosphere (Rodríguez-Lizana et al, 2008). Therefore, chopping residues provide additional field coverage while enabling pruning residues to be recycled in olive orchards.…”