Integrating nitrogen fertilization with crop residues to improve nitrogen management in intensively managed cropping systems

Figures & data

Figure 1. Three different experimental sites (a) Sherpur, Bogura (b) Chandina, Cumilla and (c) Muktagacha, Mymensingh. Cropping patterns were potato-winter rice-pre-monsoon rice-monsoon rice at the Bogura site; winter rice-pre-monsoon rice-monsoon at the Cumilla site; and maize-monsoon rice in Muktagacha, Mymensingh.

Figure 2. Weather data of Sherpur of Bogura, Chandina of Cumilla, and Muktagacha of Mymensingh (2020–21 and 2021–22). The line graph shows maximum and minimum temperature (red; maximum, blue; minimum) with secondary axis and column graph represents the rainfall (mm) in primary axis.

Figure 3. Nitrogen use efficiency model (NUE, SNMI), yield, N uptake, and kg N Mg⁻¹ yield comparison and determining the ideal N rate and demonstrated by the arrow (↓) symbol, where (a), (b), (c), (d) and (e) represents the potato, maize, winter rice, pre-monsoon, and monsoon rice respectively.

Table 1. Crop residue, N fertilizer, and their interaction effect on potato, winter rice, pre-monsoon rice, monsoon rice, and maize yield (Mg ha⁻¹) in Bogura, Cumilla, and Mymensingh, 2020–21 and 2021–22.

		Potato	Winter Rice		Pre-monsoon Rice		Monsoon Rice			Maize
2020–21		Bogura	Bogura	Cumilla	Bogura	Cumilla	Bogura	Cumilla	Mymensingh	Mymensingh
NR		33.8	5.7	6.1	4.2	3.4	4.5	4.5	4.4	8.6
CR		31.2	5.8	6.1	4.1	3.0	4.5	4.7	4.6	8.9
Level of sig. (p < 0.05)		ns	ns	ns	ns	ns	ns	ns	ns	ns
	CL	16.9 b	3.6 c	4.7 c	3.6 b	2.4 b	3.4 b	3.8 b	3.6 c	4.2 b
	FP	38.6 a	5.5 b	6.1 b	4.3 a	3.4 a	4.7 a	4.7 a	4.5 b	10.4 a
	RD	34.6 a	6.3 b	6.3 b	4.3 a	3.5 a	4.9 a	4.9 a	4.6 b	10.3 a
	1.25 RD	39.9 a	7.4 a	7.2 a	4.6 a	3.6 a	5.0 a	5.0 a	5.3 a	10.1 a
Level of sig. (p < 0.05)		***	***	***	***	***	***	***	***	***
Residue x N rate		ns	ns	ns	ns	ns	ns	ns	ns	ns
2021–22
NR		22.9	6.2	6.5	4.6	4.5	5.0	4.4	4.3	9.3
CR		24.9	6.4	6.9	4.6	4.6	5.2	4.8	4.6	9.7
Level of sig. (p < 0.05)		ns	ns	ns	ns	ns	ns	ns	ns	ns
	CL	7.4 b	4.8 c	4.8 c	3.5 b	3.2 b	3.9 b	3.7 c	2.9 c	2.5 b
	FP	28.6 a	6.2 b	7.0 b	4.8 a	4.8 a	5.3 a	4.7 b	4.7 b	11.5 a
	RD	29.4 a	6.8 ab	7.2 ab	4.9 a	4.8 a	5.4 a	4.9 ab	4.8 b	12.0 a
	1.25 RD	30.3 a	7.4 a	7.8 a	5.3 a	5.3 a	5.8 a	5.1 a	5.5 a	12.1 a
Level of sig. (p < 0.05)		***	***	***	***	***	***	***	***	***
Residue x N rate		ns	ns	ns	ns	ns	ns	ns	ns	ns

Table 2. Crop residue, N fertilizer and their interaction effect on NUE and SNMI in winter and pre-monsoon rice in Bogura and Cumilla, 2020–21, 2021–22.

		Winter Rice				Pre-monsoon Rice
		NUE		SNMI		NUE		SNMI
Bogura		2020–21	2021–22	2020–21	2021–22	2020–21	2021–22	2020–21	2021–22
NR		0.40b	0.40b	0.60a	0.60a	0.35	0.38	0.65	0.63
CR		0.44a	0.45a	0.55b	0.55b	0.40	0.36	0.61	0.65
Level of sig. (p < 0.05)		*	*	*	*	ns	ns	ns	ns
	FP	0.41	0.42	0.59	0.58	0.34b	0.29b	0.66a	0.71a
	RD	0.43	0.40	0.57	0.60	0.38ab	0.41a	0.63ab	0.59b
	1.25 RD	0.43	0.45	0.57	0.55	0.41a	0.39a	0.59b	0.61b
Level of sig. (p < 0.05)		ns	ns	ns	ns	*	**	*	**
NR	FP	0.38b	0.38	0.62a	0.62	0.31	0.32	0.69	0.68
	RD	0.43ab	0.36	0.57ab	0.64	0.36	0.44	0.64	0.56
	1.25 RD	0.39b	0.44	0.61a	0.56	0.39	0.37	0.61	0.63
CR	FP	0.43ab	0.46	0.57ab	0.54	0.37	0.27	0.64	0.74
	RD	0.42ab	0.44	0.58ab	0.56	0.39	0.39	0.62	0.62
	1.25 RD	0.47a	0.45	0.52b	0.55	0.43	0.41	0.57	0.59
Residue x N rate		*	ns	*	ns	ns	ns	ns	ns
Cumilla
NR		0.36	0.35b	0.64	0.65a	0.39	0.35b	0.64	0.65a
CR		0.40	0.42a	0.60	0.58b	0.41	0.43a	0.64	0.58b
Level of sig. (p < 0.05)		ns	*	ns	*	ns	*	ns	*
	FP	0.32c	0.37	0.68a	0.63	0.32c	0.36b	0.75a	0.80a
	RD	0.40b	0.39	0.60b	0.61	0.41b	0.37b	0.65b	0.67ab
	1.25 RD	0.44a	0.40	0.56c	0.60	0.48a	0.43a	0.53c	0.53b
Level of sig. (p < 0.05)		***	ns	*	ns	***	*	***	*
NR	FP	0.31c	0.32	0.69a	0.68	0.30	0.37abc	0.76	0.63abc
	RD	0.39b	0.34	0.61b	0.65	0.42	0.28c	0.62	0.72a
	1.25 RD	0.40b	0.38	0.60b	0.62	0.46	0.40ab	0.55	0.60bc
CR	FP	0.33c	0.41	0.67a	0.59	0.34	0.35bc	0.74	0.65ab
	RD	0.41b	0.44	0.59b	0.56	0.40	0.46a	0.67	0.54c
	1.25 RD	0.47a	0.41	0.53c	0.59	0.50	0.46a	0.51	0.54c
Residue x N rate		*	ns	*	ns	ns	**	ns	**

Table 3. Crop residue, N fertilizer and their interaction effect on NUE and SNMI in monsoon rice in Bogura, Cumilla and Mymensingh, 2020–21, 2021–22.

		Bogura				Cumilla				Mymensingh
		NUE		SNMI		NUE		SNMI		NUE		SNMI
Residue	N rate	2020–21	2021–22	2020–21	2021–22	2020–21	2021–22	2020–21	2021–22	2020–21	2021–22	2020–21	2021–22
NR		0.39	0.39	0.61	0.60	0.39	0.33b	0.61	0.72a	0.41	0.40	0.62	0.61
CR		0.41	0.41	0.60	0.59	0.39	0.37a	0.61	0.65b	0.38	0.43	0.65	0.58
Level of sig. (p < 0.05)		ns	ns	ns	ns	ns	***	ns	**	ns	ns	ns	ns
	FP	0.39b	0.35b	0.62a	0.66a	0.40	0.31b	0.60b	0.75a	0.40ab	0.38b	0.64	0.64a
	RD	0.39b	0.42a	0.62a	0.56b	0.37	0.35ab	0.63a	0.68ab	0.42a	0.43a	0.62	0.58b
	1.25 RD	0.42a	0.43a	0.58b	0.57b	0.40	0.39a	0.60b	0.62b	0.36b	0.44a	0.66	0.56b
Level of sig. (p < 0.05)		*	**	*	**	ns	*	*	**	*	**	ns	**
NR	FP	0.36c	0.32	0.64	0.68	0.43	0.30	0.57	0.77	0.41	0.35	0.63	0.67
	RD	0.38bc	0.41	0.62	0.55	0.33	0.34	0.67	0.71	0.44	0.42	0.60	0.59
	1.25 RD	0.43a	0.43	0.57	0.57	0.40	0.36	0.60	0.66	0.38	0.44	0.64	0.56
CR	FP	0.42ab	0.37	0.60	0.63	0.38	0.32	0.63	0.72	0.39	0.41	0.64	0.60
	RD	0.40abc	0.43	0.62	0.57	0.41	0.37	0.59	0.65	0.40	0.44	0.63	0.57
	1.25 RD	0.42abc	0.43	0.59	0.57	0.40	0.42	0.60	0.58	0.34	0.44	0.67	0.56
Residue x N rate		*	ns	ns	ns	ns	ns	ns	ns	ns	ns	ns	ns

Table 4. Crop residue, N fertilizer and their interaction effect on NUE and SNMI in potato and maize in Bogura and Mymensingh, respectively, 2020–21, 2021–22.

		Potato				Maize
		NUE		SNMI		NUE		SNMI
Residue	N Rate	2020–21	2021–22	2020–21	2021–22	2020–21	2021–22	2020–21	2021–22
NR		0.51b	0.46b	0.49a	0.54a	0.44b	0.49b	0.56a	0.51a
CR		0.57a	0.55a	0.43b	0.45b	0.50a	0.54a	0.50b	0.46b
Level of sig. (p < 0.05)		*	*	*	*	*	*	*	*
	FP	0.52b	0.51	0.48a	0.49	0.57a	0.56a	0.43c	0.44c
	RD	0.54ab	0.49	0.46ab	0.51	0.49b	0.52b	0.51b	0.48b
	1.25 RD	0.56a	0.51	0.44c	0.49	0.36c	0.46c	0.64a	0.54a
Level of sig. (p < 0.05)		*	ns	*	ns	***	***	***	***
NR	FP	0.48	0.47	0.52a	0.53	0.55ab	0.52	0.45de	0.48
	RD	0.51	0.45	0.49ab	0.55	0.48 cd	0.50	0.52bc	0.50
	1.25 RD	0.54	0.45	0.46abc	0.55	0.30e	0.45	0.70a	0.55
CR	FP	0.56	0.54	0.44bc	0.46	0.59a	0.59	0.41 e	0.41
	RD	0.57	0.54	0.43bc	0.46	0.50bc	0.55	0.50cd	0.45
	1.25 RD	0.59	0.56	0.41c	0.44	0.42d	0.48	0.58b	0.52
Residue x N rate		ns	ns	*	ns	**	ns	**	ns