4.4. Fertilizer recommendations
Sugarcane monocropping over the decades deteriorated nutrient index and
soil quality due to causing multi-nutrient deficiency occurs by
imbalance fertilization. Hence, targeted yield equations (TYE) ensure
balanced fertilization as doses of N, P and K were applied on the basis
of initial soil test value under the concept “Fertilizing the soilVs Fertilizing the crop” proposed by Ramamurthy and Bajaj
(1969). WZ soils needed greater amount of N than EZ and CZ for both
plant and ratoon crop due to excess N mining from the decades resulted
depleted soil Na might be due to mismatch between
applied and removal of nitrogen (Shukla et al., 2009; Shukla et al.,
2017). The greater P and K fertilizers required in plant and ratoon
crops grown in EZ soils linked to lower Pa and
Ka status caused through surface runoff (Zhao et al.,
1988; Li et al., 2007a). However, lower or even negative
P2O5 doses required in CZ and WZ soil
due to high Pa status occurs by applying excess P
fertilizers. The lower K status in EZ soils (87.8% soil sample
deficient) liable to required more K2O for achieving 100
Mg cane yield ha-1 as it removed about 280 kg K
ha-1 against applied 60 kg K2O
ha-1.