Effects of Organic Soil Amendments on Photosynthetic Traits of Black Pepper (Piper nigrum L.) in an Alluvial Soil

Table 1

Soil amendments description, composition, and rate of application for mature pepper vines.

Treatment	Description	Composition	Rate of application	Adapted from
FNPK	Control	NPK 12 : 12 : 17 chemical compound fertilizer	Standard recommended rate (Table 2)	[12]
FPJ	Fermented Plant Juice (FPJ)	1 kg of leafy vegetables such as water spinach, Chinese mustard, black pepper leaves, tapioca leaves mixed with 1 kg molasses	200 mL of FPJ in 16 litres of water per month for 100 vines	[13]
FPJBC	Fermented Plant Juice incorporated with biochar and compost (FPJBC)	FPJ plus biochar and compost	200 mL of FPJ in 16 litres of water per month for 100 vines; 2 kg of biochar applied per vine per year; 3.5 kg compost applied per vine for every 3 months	[12, 13]
FFJ	Fermented Fruit Juice (FFJ)	1 kg of fruits such as banana, papaya, pumpkin, and pepper berries mixed with 1 kg molasses	200 mL of FFJ in 16 litres of water per month for 100 vines	[13]
FFJBC	Fermented Fruit Juice incorporated with biochar and compost (FFJBC)	FFJ plus biochar and compost	200 mL of FFJ in 16 litres of water per month for 100 vines; 2 kg of biochar applied per vine per year; 3.5 kg compost applied per vine for every 3 months	[12, 13]