Effluent Irrigation of Rye and Ryegrass

The winter forage crops rye (Secale cereale) and ryegrass (Lolium multiflorum) were grown on Lakeland fine sand under irrigation with secondary municipal effluent. Irrigation rates from l in./week-4 in./week (25 mm/week-l00 mm/week) were used. Three cuttings of forage were obtained over a 2l-week growing period. Dry matter yields increased with irrigation rate, while dry matter percentage showed a decrease. Nutrient uptake generally increased with application rate, while recovery efficiency of all elements measured decreased. Recoveries of 67% and 50% of applied N occurred at l05 lb/acre (ll8 kg/ha) and 2l5 lb/acre (240kg/ha) for rye, and at 195 lb/acre (2l8 kg/ha) and 310 lb/acre (347 kg/ha) for ryegrass. The effluent was deficient in K relative to other nutrients. An irrigation rate of l in./week (25 mm/week) to 2 in./week (50 mm/week) appears suitable for production of rye or ryegrass with effluent on well-drained sandy soils.