Yield and quality of three corn hybrids as affected by broiler litter fertilization and crop maturity

Specific hybrids, fertilization and maturity impact yields and nutrient qua lity of corn silage. To address these effects, three corn hybrids (Zea mays L.) (Pioneer 3136, 3140, 3154) with five N fertilization (F) treatments we re planted for 2 years and harvested at approximately 1/3, 2/3 or 100% milk line in a split-split plot design. Main treatments were No-F, 4.5, 9.0, 13 .5 (Year 1) or 18.0 (Year 2) Mg ha(-1) of broiler litter (BrL) or 202 kg ha (-1) of NH4NO3. At harvest, milk lines and whole plant, stover and grain yi elds were determined. Whole plant and stover portions were chopped and subs ampled for subsequent nutrient component and in vitro dry matter disappeara nce (IVDMD). Milk line advanced rapidly, especially during Year I that was a dry year. Whole plant yields were greatest for the 13.5/18.0 BrL treatmen ts with no difference between 9.0 BrL and NH4NO3 treatments. Nutrient conte nt varied with fertilizer treatment and year; during Year 1, NH4NO3 treatme nts had greater CP and lower ADF values, but the 13.5/18.0 BrL had the grea test CP content in Year 2, a wetter year. Whole plant lVDMD values were gre ater for NH4NO3 than the 13.5/18.0 BrL treatments during both years, but th is occurred only during Year I for stover. Corn hybrid did not consistently affect yield, but during both years stover ADF was lower and IVDMD was hig her for Hybrid 3136. These advantages existed in the whole plant only durin g Year 1. Increased maturity enhanced grain and whole plant yield, but effe cts on nutrient quality were variable. Appropriate application rates of BrL provide comparable yields to commercial fertilizer without an adverse effe ct on nutrient composition, although digestibility may be reduced. (C) 2001 Elsevier Science B.V. All rights reserved.