Timing and Splitting of Nitrogen Compensated for the Loss in Grain Yield of Dual-Purpose Wheat Under Varied Cutting Heights

Optimizing cutting management practices for fodder is one of the most critical processes in a dual-purpose (DP) wheat system. However, nitrogen (N) dose and time of application are crucial for the success of this system. A field experiment was performed during the Rabi season 2017-18 at Amir Muhammad Khan (AMK) Research Farm, Khyber Pakhtunkhwa (Pakistan) to explore the potential of wheat (Triticum aestivum L.) as a DP crop for improving both forage and grain yields by finding out optimal cutting and nitrogen management practices for DP cropping. The three-factor study comprised nitrogen levels (120, 140, and 160 kg ha(-1)); two times of nitrogen application: two splits (sowing and cutting stage) and three splits (sowing, cutting, and 15 days after cutting); and cutting heights (uncut, cut at 0 cm, 7 cm, and 10 cm above ground level). Observations revealed that nitrogen at 160 kg ha(-1) increased green forage and dry forage yield by 56% and 45%, respectively, compared to controls. Increasing N rates up to 160 kg ha(-1) resulted in higher leaf area tiller(-1), leaf area index, grains per spike, biological yield, and 1000-grain weight. Cutting height at 10 cm showed reduced leaf area (11%), leaf area index (15%), biological yield (2.3%), and grain yield (6%) compared to the uncut treatment, whereas for cutting at 7 cm and ground level, the reduction was further increased-excluding forage yield which was 30% greater at ground level compared with 7 and about 35% greater than 10 cm cutting height. Generally, from this study, it can be concluded that N at 160 kg ha(-1), both in two or three splits, substantially enhanced wheat fodder, grain yield, and associated traits. Cutting at a height of either 10 cm or 7 cm resulted in higher grain yield as compared to ground level. Moreover, grain yield under cutting at 10 cm and 7 cm height was reduced by 3% and 6%, respectively, compared to no cut. However, the additional fodder yield from these plots compensated for the grain yield losses. This study indicated that the productivity of wheat under a dual-purpose system was found to be more economical with respect to benefit-cost ratio (BCR). Cutting treatment had a higher profitability (BCR = 4.74), which was higher than wheat sown only for grain purposes (uncut treatment) with a BCR value of 3.61.