## Materials and Methods
### Maize Test on Farm A  
Mycorrhizal and nonmycorrhizal maize seeds were sown on 7 June 2014, on two plots of 1.5 ha each per treatment. The soil had a clay loam texture (clay 64.6%, silt 18.4%, sand 17.0%) and alkaline conditions (pH 8.2, 1:5 soil/water extract), showing the following properties before seeding: total N 2.3 g kg\({}^{-1}\) (Kjeldhal method), organic matter 36.0 g kg\({}^{-1}\) (Walkley and Black method), total carbonate 30.0 g kg\({}^{-1}\) (manometric method), available phosphorus pentoxide (P\({}_{2}\)O\({}_{5}\)) 30.0 mg kg\({}^{-1}\) (Olsen method). The maize control treatment (M) was nonmycorrhizal maize that received the full dose of P and N (i.e., N 250 kg ha\({}^{-1}\), P 100 kg ha\({}^{-1}\)) and calculated on the basis of expected uptake (3.9 kg N t\({}^{-1}\) yield, and 15 P\({}_{2}\)O\({}_{5}\) t\({}^{-1}\) yields) and yield (65.0 tha\({}^{-1}\)) suggested by the Department of Agriculture of Campania Region [47]. The doses adopted were similar to those used by farmers in local practice. The full dose of P\({}_{2}\)O\({}_{5}\) was applied at seedbed preparation, while one-third of N was applied at the time of sowing and the remaining two-thirds at fourth-leaf stage, or growth stage (GS) 14 according to the BBCH (Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) scale [48]. The experimental maize test (M + m) was mycorrhizal maize that received only half the dose of N (125 kg ha\({}^{-1}\)). The maize was irrigated when required, for a total irrigation volume of 600 m\({}^{3}\) ha\({}^{-1}\). M + m and M maize were harvested on 25 September 2014 at the kernel dent ripening phase (GS85), and put into 4 silo bags: one per plot, two per treatment. The forage was chopped to 1.50 cm theoretical length of cut using the same harvester. Forty lactating buffalo were divided into groups differing only in the use of inoculated (M + m group) or control (M group) maize silage (the experimental test was 16 days long). The groups were balanced for number (20), parity (2.2 \(\pm\) 0.6 and 2.3 \(\pm\) 0.6 for M + m and M groups, respectively), days in milk (98 \(\pm\) 19 and 98 \(\pm\) 18 days), and milk production (12.0 \(\pm\) 2.4 and 12.0 \(\pm\) 4.9 kg d\({}^{-1}\) per head). Ingredients of diets (kg per day) fed to lactating buffalo were as follows: mycorrhizal silage (20 and 0, for M + m and M groups, respectively), nonmycorrhizal silage (0 and 20), meadow hay (4.5 and 4.5), mash maize (3.0 and 3.0), concentrate (a mixture based on soybean, maize, sunflower, and barley meals) (4.5 and 4.5), and a mix of vitamins and minerals (0.3 and 0.3). The chemical composition of the diets expressed as g kg\({}^{-1}\) of dry matter was as follows: crude protein 141 and 140, ether extract 26.3 and 26.4, neutral detergent fiber 380 and 373, acid detergent fiber 254, and 274, and UFL (Unite Fourragere Laird) 870 and 870. After 10 days of adapting to the diets, according to Filho et al. [(49)], dry matter intake was measured over six consecutive days on a group basis. Milk samples were automatically collected twice daily, in the morning (05:00 h) and the evening (17:00 h). The milk yield was 11.1 and 11.3 kg d\({}^{-1}\) per head, respectively, for the M + m and M groups. The animals were housed in 2 barns where they were free to move. Each barn was furnished with a feed manger, automatic drinker, and outdoor paddock. The animals were handled in a similar way in terms of feeding (once daily at 07:00 h).