BIOMASS AND NUTRIENT UPTAKE BY RICE AND WHEAT: A THREE-WAY INTERACTION OF POTASSIUM, AMMONIUM AND SOIL TYPE
M. SALEEM AKHTAR1* AND MEHRUNISA MEMON2
Abstract:
Potassium (K)-ammonium (
)
interaction for biomass production and K uptake determined by nutrient
solution may be modified by soil type due to variable clay content and
constituent clay minerals. Rice and wheat response to various
combinations of K and was
investigated in three soils in a replicated three factors factorial pot
experiment. Combinations of K 0, 300 and 600 mg kg-1 and
0, 115, and 230 mg kg-1 soil were applied in Kotly, Gujranwala, and
Lyallpur soils. Rice tillers per plant and dry matter, and K content in
various plant parts increased under the main effects (K,)
but several two-way interactions were also significant. Biomass
production was highest at the highest application
level (230 mg kg-1) for the silty clay Kotly soil and lowest for the
sandy loam Lyallpur soil. It suggests the role of clay content in
temporarily retaining cations and avoiding suppression of biomass in the
presence of .
Maximum K content in rice plant was with 300 mg K and 115 mg kg-1
soil. Interaction of K and on
K uptake was significant. The highest K content in plant tissue was at
the application level of 300 mg K kg-1 and 0.
Plant tissue K decreased with each addition of at
300 mg K kg-1 but at the highest K application of 600 mg kg-1 soil no
reduction in plant tissue K occurred. The study suggests that response
of rice and wheat in terms of biomass production and K accumulation vary
with K and levels
as well as K and
interaction changed with the soil type.
1Department of Soil Science, PMAS Arid Agriculture University Rawalpindi, Pakistan
2Department of Soil Science, Sindh Agriculture University, Tandojam, Pakistan