High reduction of erosion and nutrient losses by decreasing harvest intensity of lavender grown on slopes

• Published in: Agronomy for sustainable development 2009-04, Vol.29 (2), p.363-370
• Main Authors: RODRIGUEZ PLEGUEZUELO, Carmen Rocio, DURAN ZUAZO, Victor Hugo, MARTINEZ RAYA, Armando, FRANCIA MARTFNEZ, José Ramon, CARCELES RODRIGUEZ, Belén
• Format: Article
• Language: English
• Subjects: Agricultural sciences; Agriculture; Agronomy. Soil science and plant productions; Biological and medical sciences; Biomedical and Life Sciences; Ecology, environment; Fundamental and applied biological sciences. Psychology; Lavandula; Life Sciences; Physical properties; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Research Article; Soil erosion, conservation, land management and development; Soil science; Soil Science & Conservation; Sustainable Development; Water and solute dynamics
• ISSN: 1774-0746; 1773-0155
• DOI: 10.1051/agro:2008043

In Mediterranean countries, where rainfall is scarce and irregular, intensive agriculture promotes erosion and nutrient losses from soil, ending eventually in contamination of water bodies. Wild shrubs may protect the soil against the erosivity of raindrops. However, some shrubs such as wild lavender are traditionally harvested by uprooting the entire plant. Thus, we studied here the impact of harvesting only a part of the plant biomass. Cultivating lavender, Lavandula lanata L., in erosion plots in Lanjarón, Granada, Spain, we studied the effect of two harvest intensities of 25% and 50% of the plant biomass, on soil erosion, runoff, nutrient loss (NPK) and soil-water dynamics. Our results show that decreasing the harvest intensity from 50% to 25% reduced soil loss by 67%: from 143 to 46 kg soil ha −1 yr −1 . Water runoff was also decreased by 59%: from 13 to 5 mm yr −1 . These findings demonstrate that the rational harvest of cultivated aromatic plants protected the soil against erosion due to the reduction of soil-particle detachment by raindrop impact, and consequently avoided mechanical soil movement. Further, decreasing the harvest intensity from 50% to 25% reduced N losses by 65%, P losses by 42% and K losses by 64%. Soil-water content at 5, 10 and 20 cm deep was also higher for a harvest intensity of 25% than for a harvest intensity of 50%. In conclusion, this study supports the cultivation of lavender instead of wild harvest, following a rational harvest of biomass for reducing erosion and pollution as well as conserving soil-water content.