Influence of varying nitrogen levels on performance of wheat (Triticum aestivum L.) under semi-arid hot climate of Kandahar, Afghanistan

Abstract

An experiment was conducted during winter season of 2014-15 at Tarnak Research Farm of
Afghanistan National Agricultural Sciences and Technology University (ANASTU), Kandahar,
Afghanistan. Soil of the experimental site was sandy clay loam in texture with slightly alkaline (pH
8.3) in reaction having cation-exchange capacity of 80.58 meq 100g–1 and electrical conductivity of
0.21 dSm–1. The initial N, P and K contents were in low to medium range. The treatments consisted
of seven nitrogen rates viz., 0, 80, 100, 120, 140, 160 and 180 kg ha–1 was replicated thrice using a
RCBD. Significantly higher growth parameters viz., plant height (85.1 cm), dry matter production
(2882 g m–2), number of tillers m–2 (335) and number of spikes–1 (321) were recorded with application
of 180 kg N ha–1 in comparison with other N rates. Yield attributing characteristics viz., spike length
(12 cm), spikelets spike–1 (20.3), grains spike–1 (46.6), weight of single spike (2.5 g), grain weight
spike (1.83 g) and 1000-grain weight (39.2 g) as well as grain yield (4.47 t ha–1), biological yield (10.9
t ha–1) and harvest index (41%) were significantly higher with application of 160 kg N ha–1 than
other higher and lower N rates.