Effect of potassium nutrition on distribution of ionic constituents among plant organs of cotton (Gossypium hirsutum L.)

A field experiment was conducted to determine the effects of potassium nutrition on the distribution of cations and anions in cotton (Gossypium hirsutum L.) plant under irrigated conditions. The treatments consisted of (a) four cultivars (CIM-448, CIM-1100, Karishma, S-12) (b) four rates of potassium fertilizer (0, 62.5, 125.0, 250.0 kg K+ ha(-1) and two sources of potassium fertilizer [sulphate of potash (K2SO4,) and muriate of potash (KCl)] were arranged in a split plot design. The plants were harvested at maturity. The percentage distribution of K+ N, P, Ca2+, Mg2+, Na+, Cl+, and SO42-S nutrients were determined in various plant organs. Crop receiving 250 kg K+ ha(-1) maintained nutrients in different proportions in various organs at maturity. Nutrient distribution were in decreasing order: K+ [burs (31.9%), seed (23.1%), stems (20.5%), leaves (14.2%), lint (10.4%)], N [seed (67.6%), leaves (13.9%), stems (11.8%), burs (4.7%), lint (2.0%)], P [seed (76.2%), stems (7.3%), burs (7.0%), leaves (5.1%), lint (4.4%)], Ca2+ [leaves (39.0%), stems (36.0%), seed (16.5%), burs (7.0%), lint (1.5%)], Mg2+ [seed (32.1%), stems (28.8%), burs (19.3%), leaves (18.6%), lint (1.2%)], Na+ [stems (62.7%), leaves (18.7%), seed (10.3%), burs (7.7%), lint (0.6%)], Cl- [stems (44.0%), leaves (36.5%), burs (16.3%), seed (2.5%), lint (0.7%)]; and SO42-S [seed (45.1%), leaves (34.6%), lint (9.4%), stems (5.5%), burs (5.4%)]. The addition of K-fertilizer in the form or KCl and/or K2SO4 caused significant increase in Cl- and SO42--S with respect to their accompanying anions. Mg2+ and Na+ nutrients were greatly affected by K+-sources.