Impact of Indian Mustard (Brassica juncea) and Flax (Linum usitatissimum) Seed Meal Applications on Soil Carbon, Nitrogen, and Microbial Dynamics

Table 4

Microbial lipid biomarkers in soil 3 and 28 days after amendment with various rates of flax or mustard seed meal or sorghum-sudangrass biomass.

Time; (days)	Amendment rate (%)	Biomass type	TL-FAME^1 markers (nmol g^−1 soil)
			Total bacteria	Gram + bacteria	Gram − bacteria	Fungi	Total^2	Fungal : bacterial ratio
3	0	Unamended	15.86^a	7.64^a	8.22^a	9.30^a	25.16^a	0.59^a
	0.5	Flax	30.21^bc	15.54^b	14.68^a	23.19^b	53.40^b	0.77^a
	0.5	Mustard	25.83^b	18.29^b	7.54^b	113.36^c	139.20^c	4.44^b
	0.5	Sorghum-sudangrass	33.69^c	25.02^c	8.67^a	86.84^d	120.53^d	2.57^c
3	0	Unamended	15.86^a	7.64^a	8.22^a	9.30^a	25.16^a	0.59^a
	5.0	Flax	57.80^b	35.54^b	22.25^b	40.95^b	98.74^b	0.71^b
	5.0	Mustard	42.82^c	24.00^c	18.82^bc	206.10^c	248.91^c	4.80^c
	5.0	Sorghum-sudangrass	56.37^b	42.79^b	13.58^ac	2.31^d	58.69^d	0.04^d
28	0	Unamended	16.66^a	8.21^a	8.44^a	16.09^a	32.75^a	0.97^a
	0.5	Flax	34.45^b	18.05^b	16.40^b	41.92^ab	76.38^ab	1.21^ab
	0.5	Mustard	45.19^b	25.96^c	19.23^b	34.42^ab	79.61^ab	0.76^a
	0.5	Sorghum-sudangrass	33.74^b	22.42^bc	11.32^a	73.04^b	106.78^b	2.51^b
28	0	Unamended	16.66^a	8.21^a	8.44^a	16.09^a	32.75^a	0.97^a
	5.0	Flax	83.66^bc	49.14^b	34.52^b	99.58^a	183.24^b	1.19^a
	5.0	Mustard	120.34^b	97.62^c	22.72^ab	202.59^b	322.92^c	1.69^a
	5.0	Sorghum-sudangrass	81.67^c	59.58^b	22.10^ab	103.26^a	184.93^b	1.34^a

Means within a column, for a specific amendment rate (including the unamended control) and day, followed by the same letter(s) are not significantly different at 𝑃<0.05.
¹TL-FAME: total lipid-fatty acid methyl ester analysis.
²Total TL-FAME marker represents the sum of Gram-positive bacteria, Gram-negative bacteria, and fungi for a given community.