Original scientific paper
Initiation date and nitrogen rate for stockpiling semi-natural mountain grassland
2018, 19 (3) p. 544-556
Reducing costs in livestock farming can be achieved by stockpiling. Stockpiling is managing a pasture or hay to accumulate forage produced during the growing season to be grazed at a later time. The objective of this study was to identify stockpile initiation dates and N fertilization rates that optimize stockpile yield and quality of semi-natural mountain grassland in Croatia. A randomized complete block design with four replications was applied. Stockpile initiation dates were 15 June, 1 July, 15 July and 1 August. Nitrogen fertilization treatments were 0, 35, or 70 kg*ha-1 applied as ammonium nitrate on the date of stockpile initiation for each treatment. In late fall before snowy period were determined dry matter yield (DM), botanical composition, crude protein (CP), neutral (NDF) and acid detergent fibre (ADF) content. Stockpile forage DM yield was generally greater from earlier stockpile initiation dates (2.91, 2.18, 2.05 and 1.44 t DM*ha-1 for 15 June, 1 July, 15 July and 1 August stockpile initiation dates, respectively; LSD at 0.05 = 0.24). Stockpile forage DM yield was the greatest with 70 kg N*ha-1 and the lowest with 0 N fertilization, averaging 1.78, 2.23 and 2.43 t DM*ha-1 (LSD at 0.05 = 0.14) for 0, 35, and 70 kg N*ha-1, respectively, when averaged across stockpile initiation dates and years. Crude protein tended to increase and neutral detergent fiber tended to decrease as stockpile initiation was later in the season. These results indicate that initiating stockpiling of seminatural mountain grassland about first half of July with 35 kg N*ha-1 optimizes stockpiled grassland in the North-West region of Croatia.