Effect of abandoning highland grazing on nutrient balances and economic performance of Italian Alpine dairy farms

摘要

In many European mountain areas, such as the Alps, highland grazing is declining. In addition to its effect on natural landscape and biodiversity, abandoning highland grazing may affect dairy-farm profitability and have environmental consequences in the lowland. The objective of this study was to assess economic and environmental effects of abandoning highland grazing of dairy herds in the central Italian Alps. We compared environmental and economic indicators of 12 farms that applied highland grazing (HG) of dairy cows with those of 16 farms that applied no grazing (NG), neither in highland nor in lowland. Environmental indicators used were nitrogen (N) and phosphorus (P) surplus per ha of land or per ton of FCM (fat-corrected milk). Economic indicators used were labor income of the farm family (k(sic) per farm) or labor income per ton of FCM ((sic)ton(-1) FCM). Compared with HG farms, NG farms had larger total milk production (370.7 vs 141.4 ton FCM), higher production per ha (13.9 vs 8.4 ton FCM ha(-1)) and higher annual milk yield per cow (6.3 vs 4.4 ton FCM). Because of the extensive manner of milk production in highland of HG farms, the NP surplus per ha of highland was negligible (6.4 N and -0.2 P ha(-1) year(-1)), and, therefore, not further considered. The N surplus averaged 186 kg N ha(-1) year(-1) for NG farms compared with 137 kg N ha(-1) year(-1) for lowland of HG farms. The P surplus averaged 30 kg P ha(-1) year for NG farms compared with 24 kg P ha(-1) year(-1) for lowland of HG farms. A high milk production per ha and a low % FSS (feed self-sufficiency) were associated with a high NP surplus, whereas the grazing system did not affect NP surplus per ha. Labor income per farm was lower for HG farms (30.3 k(sic)) than for NG farms (72.2 k(sic)), but expressed in euro per ton FCM, labor income was higher for HG (0.24(sic)) than for NG farms (0.16(sic)). A smaller farm size in the lowland and a lower milk production per ha lowland explained the lower labor income for FIG farms compared with NG farms. Additional revenues from highland grazing, i.e. high-value cheese and grazing subsidies, caused higher labor income per ton FCM for FIG than for NG farms. Hence, farmers tend to increase their net farm income by increasing their milk production per farm, via increasing their area of lowland and/or their milk production per ha lowland, while at the same time they abandon highland grazing. As enlargement of the lowland area is hampered by increasing urbanization of the valleys of the Italian Alps, farmers probably will increase their milk production per ha lowland. A higher milk production per ha lowland, however, will increase the environmental impact in the lowlands