Effect of Different Organic Manures and Fertilizers on Growth and Yield of Knol-Khol (Brassica oleracea var. gongylodes L.)

Abstract

A field experiment was carried out to investigate the effect of different manures and fertilizers on the growth and yield of knol-khol (Brassica oleracea var. gongylodes) at Dr. Pumendu Gain Field Laboratory of Agrotechnology Discipline, Khulna University, Khulna from November 2014 to February 2015. The single factor experiment comprised of different types of fertilizers and manures viz., T₀ (Control), T₁ (Recommended doses of NPK), T₂ (Cow dung), T₃ (Vermicompost), T₄ (Poultry manure), T₅ ( 50 % Cow dung + 50 % NPK), T₆ (50% Vermicompost + 50% Cow dung), T₇(50% Vermicompost + 50 % Poultry manure) and T₈(25% Cow dung+ 25% Vermicompost+ 25% Poultry manure + 25% NPK). The Experiment was laid out in Randomized Complete Block Design (RCBD) with four replications. The maximum plant height was obtained from the treatment T₁ (Recommended doses of NPK) at 25, 35 and 45 DAT. The maximum spread of canopy was 36.75 cm, 52.50 cm and 66.05 cm from the treatment T₃ (Vermicompost), T₇ (50% Vermicompost + 50 % Poultry manure) and T₂ (Cow dung), respectively. The maximum economic yield (21.92 t/ha) and biological yield (40.083 t/ha) were found in the treatment T₁ (Recommended doses of NPK) and T₇ (50 % Vermicompost + 50 % Poultry manure), respectively. Highest benefit cost ratio (3.07) was obtained from the treatment T₁ (Recommended doses of NPK) which was statistically similar with the treatment poultry manure (2.89) and Cow dung (2.73). The minimum benefit cost ratio (0.57) was obtained from the treatment T₃ (Vermicompost) which indicates that high cost of vermicompost affect net return severely. Although, recommended doses of NPK produced maximum benefit cost ratio, the treatment T₄ (Poultry manure) and T₂ (Cow dung) are very close to T₁ (Recommended doses of NPK) and also statistically similar. So, we can consider the treatment T₄ (Poultry manure) and T₂ (Cow dung) for our soil health, environmental benefits and ecological safety.