The Effect of Different Irrigation Regimes on Chlorophyll Content (SPAD) in Silage Maize Grown by Organic Fertilization

Soil moisture is one of the environmental factors affecting microbial activity that causes

carbon mineralization. In frequent irrigation (low regime), it is expected that mineralization and therefore

nitrogen release will increase in the surface soil where farm (cattle) manure with high organic matter is

mixed. Nitrogen is the main source of nutrients for plant growth and high yields in silage maize. There is a

direct relationship between chlorophyll meter (SPAD) measurements used to determine the leaf chlorophyll

content, which affects the net photosynthesis rate, and nitrogen sufficiency. In this study, the seasonal

variation of SPAD values in silage maize applying three different irrigation regimes (irrigations when "real

time crop evapotranspiration - effective precipitation" value reached to 20, 40 and 60% of the available

water) in two different fertilizations (organic and mineral) treatments were investigated. As a result, the

SPAD values decreased with the increase in the irrigation regime, the SPAD values were determined higher

in the organic fertilization compared to the mineral fertilization, and resulting in more silage yield.