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

Table 4

Organic amendments on soil total organic carbon, total nitrogen, C/N ratio, and available phosphorus of mature vines farm for two years of observation.

Property	Value obtained
	FNPK	FPJ	FPJBC	FFJ	FFJBC	FNPK	FPJ	FPJBC	FFJ	FFJBC
	-------------------------------2017---------------------------------					--------------------------------2018--------------------------------
TOC (%)	1.13 ± 0.15^c	1.19 ± 0.14^c	3.42 ± 0.17^b	1.17 ± 0.08^c	3.63 ± 0.08^a	1.06 ± 0.10^b’	1.11 ± 0.11^b’	3.68 ± 0.18^a’	1.19 ± 0.06^b’	3.75 ± 0.15^a’
Total N (%)	0.79 ± 0.08^a	0.16 ± 0.05^b	0.14 ± 0.03^b	0.14 ± 0.03^b	0.15 ± 0.04^b	0.85 ± 0.05^a’	0.17 ± 0.03^b’	0.16 ± 0.04^b’	0.14 ± 0.02^b’	0.15 ± 0.01^b’
C/N ratio	1.45 ± 0.28^c	7.72 ± 2.21^b	25.79 ± 5.53^a	9.13 ± 2.13^b	25.02 ± 5.67^a	1.26 ± 0.11^c’	6.84 ± 1.32^b’	24.92 ± 6.50^a’	8.50 ± 1.04^b’	24.85 ± 2.31^a’
Available P (mg/kg)	136.85 ± 26.48^b	251.81 ± 77.53^a	193.85 ± 100.74^ab	153.45 ± 15.62^b	165.38 ± 17.91^b	155.37 ± 24.21^ab’	124.14 ± 26.88^c’	165.25 ± 29.18^a’	137.89 ± 24.96^bc’	173.72 ± 8.10^a’

Note. Treatments are FNPK–compound fertilizer control, FPJ–Fermented Plant Juice, FPJBC–Fermented Plant Juice incorporated with biochar and compost, FFJ–Fermented Fruit Juice, and FFJBC–Fermented Fruit Juice incorporated with biochar and compost (mean + SE, n = 15). Note. Means with the same letter superscript within rows are not statistically different using Tukey’s at probability level. Letters without prime represent year 2017 and single prime superscript represents year 2018.