Table 2.

The interaction impacts of the soil application of biochar × foliar-spraying of chitosan under varying soil moisture levels on the chemical compositions of the yarrow essential oil during two years of study.

Row	Compositions	RI	Experimental treatments												p-Value
			Irrigation at 80–85% F.C				Irrigation at 60–65% F.C				Irrigation at 40–45% F.C
			Non-Biochar		Biochar		Non-Biochar		Biochar		Non-Biochar		Biochar
			Non-Chitosan	Chitosan	Non-Chitosan	Chitosan	Non-Chitosan	Chitosan	Non-Chitosan	Chitosan	Non-Chitosan	Chitosan	Non-Chitosan	Chitosan
1	α-Pinene	939	9.07j ¶	9.63hi	9.92gh	9.39ij	10.05fg	10.88e	10.31f.	11.29d	12.05c	12.87b	13.13ab	13.39a	0.01*
2	Camphene	954	0.66h	0.85g	1.00f.	1.08ef	1.34d	1.17e	1.42d	1.55c	1.63bc	1.66bc	1.75b	2.19a	0.01*
3	Sabinene	975	1.73j	1.84i	1.94h	0.98k	2.34d	2.42c	2.70a	2.57b	2.07g	2.21ef	2.16f.	2.29de	0.000**
4	β-Pinene	979	1.44j	1.69i	1.63i	1.83h	2.40g	2.55ef	2.51f.	2.61e	2.73d	2.94c	3.22b	3.60a	0.000**
5	β-Myrcene	985	3.58i	3.82h	3.98gh	3.89h	4.09fg	4.23f.	4.27f.	4.60e	4.83d	5.03c	5.20b	5.73a	0.02*
6	α-Phellandrene	1003	2.03g	2.15f.	2.07g	1.23h	2.25e	2.38d	2.33d	2.44c	2.55b	2.61a	2.60ab	2.56ab	0.03*
7	p-Cymene	1029	0.28g	0.33f.	0.29g	0.36e	1.37c	1.42b	1.40b	0.44d	1.50a	1.51a	1.51a	1.49a	0.000**
Sum of hydrocarbon monoterpenes			18.79	20.31	20.83	18.76	22.84	25.05	24.94	25.50	27.36	28.83	29.57	31.10
8	1,8-cineole	1031	9.33h	10.22f.	10.40f.	9.84g	12.79d	13.25c	13.40c	11.55e	14.78b	15.12ab	15.29a	15.34a	0.01*
9	Pinocarveol < trans- >	1139	0.86h	0.90h	0.87h	0.94g	2.24b	2.41a	2.43a	1.52f.	2.00e	2.15c	2.10d	2.23b	0.000**
10	Verbenol < trans- >	1144	0.13i	0.17h	0.20g	0.22g	1.24e	1.27d	1.29d	0.31f.	1.33c	1.36b	1.34bc	1.45a	0.000**
11	Camphor	1146	2.90h	3.22g	3.08g	3.55f.	5.51c	5.99b	6.17ab	6.30a	3.83e	4.38d	4.00e	4.51d	0.000**
12	Borneol	1169	5.50gh	5.78g	5.57g	5.13h	6.33f.	8.78e	9.38d	6.40f.	10.52c	10.88c	12.71b	14.79a	0.000**
13	Terpinen-4-ol	1177	1.87j	2.04i	1.95ij	2.19h	2.37g	2.90e	2.74f.	3.15d	3.21d	3.79c	3.96b	4.18a	0.000**
14	Bornyl acetate	1285	2.13k	2.72i	2.59j	2.83h	3.74g	4.97d	4.56e	4.31f.	5.22c	5.35b	5.33b	7.02a	0.000**
Sum of oxygenated monoterpenes			22.72	25.05	24.66	24.71	34.22	39.57	39.97	33.57	40.89	43.03	44.73	49.52
Sum of hydrocarbon and oxygenated monoterpenes			41.51	45.36	45.49	43.46	58.06	64.62	64.91	59.04	68.25	71.86	74.3	80.77
15	Longifolene	1400	0.73b	0.78ab	0.86a	0.93a	0.59c	0.71b	0.65bc	0.67bc	0.42d	0.48d	0.53cd	0.56c	0.04*
16	Germacrene-D	1479	1.28a	1.34a	1.33a	1.29a	0.98b	1.10b	1.06b	1.17ab	0.75c	0.87bc	0.79c	0.96b	0.02*
17	α-Curcumene	1481	2.63b	2.82b	2.68b	3.47a	1.20d	0.47e	1.70d	0.81d	1.94c	1.01d	2.33bc	1.98c	0.000**
18	β-Bisabolene	1509	11.68b	12.05ab	12.96a	13.12a	9.98bc	9.60bc	8.80c	10.89b	7.85c	8.19c	5.70d	1.37e	0.001**
19	delta-Cadinene	1521	1.68a	0.81bc	1.05b	1.26b	1.20b	0.60	1.39ab	1.47ab	0.69c	0.87bc	1.03b	1.11b	0.02*
20	α-Calacorene	1546	1.87b	1.99ab	2.09ab	2.56a	1.46bc	0.73cd	0.57d	0.82c	0.92c	0.54d	1.11c	1.36bc	0.01*
21	α-Bisabolene < cis- >	1548	1.85a	1.96a	2.00a	2.04a	1.44b	1.52b	1.56b	1.49b	1.58b	1.69ab	1.61ab	1.75ab	0.02*
Sum of hydrocarbon sesquiterpenes			21.72	22.75	23.97	25.65	16.84	17.73	16.72	19.32	14.15	15.12	13.11	9.08
22	Nerolidol	1538	7.86b	8.45a	8.21ab	8.44a	6.16d	5.76de	5.48e	6.9c	4.72f.	4.51f.	3.62g	1.00h	0.000**
23	Caryophyllene oxide	1579	11.68c	12.05b	12.36ab	13.11a	9.97e	9.59f.	8.79g	10.88d	7.85i	8.18h	5.69j	1.36k	0.000**
24	Guaiol	1595	5.02a	5.22a	5.35a	5.57a	2.24b	2.71b	2.93b	3.82b	1.04c	1.25c	0.67d	2.07b	0.000**
25	Spathulenol	1635	1.38a	1.52a	1.51a	1.46a	1.14b	1.28b	0.24e	0.35e	0.85d	1.04c	0.96c	1.09c	0.02*
26	Chamazulene	1723	4.08b	5.16a	4.43b	5.39a	2.61d	2.91cd	2.77d	3.61c	1.58e	1.83e	2.10d	2.36	0.000**
Sum of oxygenated sesquiterpenes			30.02	32.40	31.86	33.98	22.12	22.25	21.21	26.56	15.77	16.46	14.04	7.88
Total			93.24	99.58	99.86	99.95	96.02	99.84	99.76	99.86	98.17	99.87	99.48	97.58

¶ Different letters within a row indicate significant difference at p < 0.05 according to Duncan’s test.

*: Significant at the five percent level and **: Significant at the one percent level.