Marcella Biddoccu

Evaluation of Erosion Intensity and Some of Its Consequences in Vineyards from Two Hilly Environments Under a Mediterranean Type of Climate, Italy

Giuseppe Corti1, Eugenio Cavallo2, Stefania Cocco1, Marcella Biddoccu2, Giorgia Brecciaroli1 and Alberto Agnelli3 1Dipartimento di Scienze Ambientali e delle Produzioni Vegetali, Facoltà di Agraria. Università Politecnica delle Marche, Ancona; 2Istituto per le Macchine Agricole e Movimento Terra, Consiglio Nazionale delle Ricerche, Torino; 3Dipartimento di Scienze Agrarie ed Ambientali, Facoltà di Agraria. Università degli Studi di Perugia, Perugia; Italy

Relationship between runoff and soil losses with rainfall characteristics and long-term soil management practices in a hilly vineyard (Piedmont, NW Italy)

Abstract Runoff and soil losses caused by natural rainfall events were monitored over a 10-year observation period in three experimental vineyard plots located in Alto Monferrato, a vine-growing area in Piedmont (NW Italy). The plots are characterized by a slope of about 15% and a soil classified as Typic Ustorthents, fine-loamy, mixed, calcareous, mesic. Each of them was managed with a different inter-row soil management practice: conventional tillage (CT), reduced tillage (RT) and controlled grass cover (GC), respectively. The rainfall characteristics, runoff discharge and concentration of soil in the water were measured. More than 150 rainfall events producing runoff and 63 erosive events were recorded. The data set was elaborated to investigate the relationships between runoff and soil losses with rainfall amount, duration and intensity, and to evaluate the effects of soil management methods. The amounts of water and soil that ran off the vineyard in the study period varied according to the season, rainfall characteristics and soil surface conditions. The highest soil losses were observed for tilled plots, with values of 111.5 and 207.7 Mg ha−1 in the CT and RT plots, and only 25.6 Mg ha−1 for GC treatment. The worst soil management practice was found to be the RT, whereas the GC was able to reduce soil lost from inter-rows in every season of the year, reaching the best effectiveness in summer (reduction greater than 90%). In addition, GC reduced runoff by 35% compared with the CT plot, showing a greater performance in summer and losing efficacy in autumn. A lower runoff reduction of 11% was observed in RT.

Effects of rows arrangement, soil management, and rainfall characteristics on water and soil losses in Italian sloping vineyards

ABSTRACT Erosional processes are highly affected by seasonal climatic fluctuations and soil management practices. Controlled grass cover is one of the most used soil conservation practices adopted in temperate climates, even if the protective effect of grass cover may decrease according to seasonal pattern. This technique is effective and, thus, widely adopted in the inter‐rows of orchards such as olives, citrus or vineyards. This study reports the erosive events recorded in two different rain‐fed hillslope vineyards with different rows orientation located in the Monferrato region, NW Italy. The study is addressed at compare the effects of different inter‐row managements and rainfall characteristics on runoff and soil loss in hillslope vineyards (average slope from 15% to 35%). Rainfall, runoff and erosion variables were monitored in hydraulically bounded vineyard plots, where the inter‐rows were managed with tillage and grass cover. Seventy‐two erosive events were recorded in the period 1992–1996 in two vineyard plots with rows along the contour lines while 86 erosive events were recorded in two plots with rows up‐and‐down the slope from 2000 to 2014 (158 erosive events and four plots in total). Events were classified according to rainfall characteristics as “long‐lasting”, “intense” and “normal”. In plots with rows along the contour lines, “intense” events were responsible for the highest mean soil loss in tilled plots (0.7 Mg ha−1) with very high erosion rates (12.3 Mg ha−1) observed during a single storm. In plots with rows up‐and‐down the slope the highest erosion rates, 21.2 and 3.4 Mg ha−1, were recorded during fall “long‐lasting” events in the tilled and grass cover plots respectively. The grass cover proved to be effective in decreasing runoff and soil losses during most of the events (at least 68% and 61% of the occurrences, respectively) reducing soil losses especially during summer storms when most of the “intense” events occured. Furthermore, the results show the fundamental role of contour‐slope row orientation in reducing runoff and soil losses, disregarding the inter‐rows soil management that is adopted. HighlightsGC effectiveness varies according to the type of rainfall event and row orientation.Rows orientation along contour lines prevents runoff also when CT is adopted.Highest runoff and soil losses depend on “long‐lasting” or “intense” events.Rainfall depth and rainfall maximum intensity count in predicting erosion rate.

Reducing soil compaction after thinning work in agroforestry plantations

Afforestation of marginal farmland with fast-growing tree species is a cost-effective way to produce wood fiber for industrial and energy use. The final harvest is often performed with terrain chipping, in order achieve high productivity and minimum-cost supply. Several machine manufacturers have developed new chipper models, specifically designed for this practice in agroforestry plantations. Soil impacts, particularly soil compaction, represent a concern in such practice. This study evaluated the impact of terrain chipping work on soil compaction in agroforestry plantations. This study tested two different options for the chipper, and namely: a new all-road chipper specifically designed for agroforestry plantations (evaluated under two tire-pressure configurations) and capable of both cross-country and road traffic, and a high-mobility chipper truck. In contrast, one option was tested for the chip shuttle, which consisted in a farm tractor equipped with a two-axle trailer. The four treatments were tested on three different sites, representing the most common soil conditions encountered in the new agroforestry plantations. Soil texture ranged from loam to sandy loam. The occurrence of soil compaction in the upper 30 cm of the soil was evaluated with two different methods: bulk density determination and penetration resistance sampling. Measurements were conducted in the machine tracks after a single pass. The two methods seemed to give contradictory results, especially in two of the three test sites. In general bulk density seemed more sensitive to changes than penetration resistance after a single passage. Bulk density measurements showed that the all-road chipper at low tire pressure and the chipper truck caused soil compaction at almost all sites. In contrast, the all-road chipper at standard tire pressure and the chip shuttle were much gentler on the soil. The limited increments found in this study are likely dependant on a relatively high soil density before traffic. The higher impact of the all-road chipper after reducing tire pressure is contrary to expectations, probably due to the use of relatively stiff tires that may deny the benefits of deflation. This study indicates that wellorganized terrain chipping may not cause such high soil compaction levels as to jeopardize tree root development and growth, despite the heavy weight of the equipment used for this task. In that regard, the specially-designed all-road chipper performs better than the chipper truck.

Effects of Soil Management on Long-Term Runoff and Soil Erosion Rates in Sloping Vineyards

Runoff and soil losses caused by natural rainfall events were monitored over a 12-year period in an experimental vineyard located in Alto Monferrato, a vine-growing area of Piedmont (NW Italy). The measurements were carried out on three plots, each of which was managed with a different inter-row soil management practice: conventional tillage (CT), reduced tillage (RT) and controlled grass cover (GC), respectively. The annual average runoff coefficients were 17.4 % in CT and 15.3 % in RT, while in the GC plot it was limited to 10.3 %. The highest soil losses were observed for the tilled plots, with average yearly erosion rates of 10.4 and 24.8 Mg ha−1year−1 in the CT and RT plots. Only 2.3 Mg ha−1year−1 were recorded for GC treatment. The protective role of grass cover will be more and more relevant, taking in account climate changes that predict increase in rainfall intensity and erosivity. The evaluation of the effect of different conservation measures on the runoff and soil erosion, in relation with future climate scenarios, would be a useful to support soil management decisions in vineyards.