Effect of polyaspartic acid and different dosages of controlled-release fertilizers on nitrogen uptake, utilization, and yield of maize cultivars

Figures & data

Figure 1. Yield of XY688 and JF2 under different fertilization ratio (a); Variation trend of dry matter of XY688 at different growing stages (b) and Variation trend of dry matter of JF2 at different growing stages (c)

Table 1. Dry matter accumulation and ratio of maize in different growth stages

Treatments		Sowing to jointing		Jointing to silking		Silking to dough		Dough to maturity
		DMA(g/plant)	RTDA%	DMA(g/plant)	RTDA%	DMA(g/plant)	RTDA%	DMA(g/plant)	RTDA%
XY688	PASPN	9.95 ± 3.48 a	2.81	140.02 ± 6.22 a	42.40	143.09 ± 6.1 b	40.45	60.6 ± 7.5 a	17.15
	N0	5.71 ± 1.24 b	1.79	131.14 ± 15.72 b	42.95	140.8 ± 3.1 b	44.19	40.94 ± 1.3 d	12.85
	N180	5.69 ± 0.39 b	1.68	140.94 ± 9.14 a	43.36	147 ± 3.6 b	43.47	44.56 ± 7 c	13.18
	S180	3.27 ± 0.56 c	0.98	134.83 ± 8.73 b	41.15	154.4 ± 1.3 a	46.00	43.11 ± 8.6 c	12.85
	SU3	4.04 ± 0.82 c	1.17	133.24 ± 7.04 b	39.73	157.44 ± 1.8 a	45.56	50.8 ± 9.28 b	14.72
	SU5	3.95 ± 0.45 c	1.16	141.31 ± 14.17 a	42.60	145.36 ± 2.6 b	42.62	50.4 ± 1.1 b	14.78
	SU7	3.8 ± 0.25	1.10	140.88 ± 6.94 a	41.76	150.86 ± 3.7 a	39.84	50.92 ± 1.9 b	14.70
Average	5.20		1.53	137.48	42	148.42	43.16	48.76	14.32
JF2	PASPN	4.56 ± 1.26 a	1.36	142.92 ± 3.84 a	44.01	133.49 ± 7.9 c	44.58	54.12 ± 9.8 a	16.15
	N0	4.07 ± 1.29 b	1.30	132.23 ± 5.38 b	43.52	139.64 ± 9.6 c	45.57	44.58 ± 1.0 c	11.90
	N180	4.84 ± 1.09 a	1.47	125.07 ± 4 b	39.47	151.17 ± 5.9 b	46.62	48.05 ± 1.7 c	14.60
	S180	4.23 ± 0.17 b	1.29	128.77 ± 3.83 b	40.66	152.5 ± 2.2 b	46.75	41.64 ± 1.3 c	12.73
	SU3	3.76 ± 0.64 b	1.15	124.77 ± 3.4 b	39.33	152.79 ± 9 b	52.21	45.5 ± 9.8 b	13.92
	SU5	3.69 ± 0.16 b	1.14	115.06 ± 3.09 c	36.73	168.78 ± 5.1 a	47.79	35.75 ± 9.5 d	11.06
	SU7	3.97 ± 0.38 b	1.16	119.21 ± 3.74 c	36.13	162.93 ± 4.8 a	47.81	54.84 ± 1.4 a	16.09
Average	4.16		1.27	126.85	39.98	151.61	47.33	46.35	13.78

Different lowercase letters mean significant difference at 0.05 level, while values with the same letter mean insignificant difference.

Table 2. Nitrogen content in different parts of maize at silking stage and ripening stage

Cultivar	Treatment	N content at silking (mg/g)			N content at maturity (mg/g)
		Leaf	Stem	Total	Leaf	Stem	Grain	Total
XY688	PASPN	1.12 ab	1.99 b	3.11 ab	0.48 b	0.42 b	3.14 a	4.05 a
	N0	0.99 b	1.50 c	2.50 b	0.45 b	0.45 b	2.47 c	3.45 c
	N180	1.20 a	1.85 b	3.04 ab	0.61 a	0.43 b	3.00 b	4.18 a
	S180	1.03 ab	1.99 b	3.03 ab	0.53 ab	0.39 b	2.99 b	4.02 b
	SU3	0.85 b	2.57 a	3.42 a	0.49 b	0.76 b	3.03 a	4.31 a
	SU5	1.18 a	2.16 b	3.34 a	0.47 b	0.81 a	2.76 b	4.08 a
	SU7	0.82 b	2.07 b	2.89 b	0.35 c	0.56 b	2.97 b	3.96 b
JF2	PASPN	0.66 b	1.70 b	2.36 b	0.37 b	0.48 a	3.16 a	4.05 a
	N0	0.96 a	1.60 b	2.56 b	0.53 a	0.51 a	2.31 c	3.37 b
	N180	0.98 a	1.80 b	2.78 a	0.47 b	0.42 a	2.92 ab	3.98 a
	S180	0.78 a	2.06 a	2.84 a	0.56 a	0.46 a	2.81 b	3.98 a
	SU3	0.79 b	1.96 a	2.75 a	0.44 b	0.47 a	2.83 b	3.91 a
	SU5	0.80 b	2.06 a	2.86 a	0.54 a	0.31 b	2.79 b	3.78 a
	SU7	0.94 ab	1.65 b	2.59 b	0.55 a	0.44 a	2.87 b	4.00 a

Different lowercase letters mean significant difference at 0.05 level, while values with the same letter mean insignificant difference.

Table 3. Nitrogen accumulation in different organs of maize at Suckling stage and complete stage

		Milk stage				Maturity stage
Cultivar	Treatments	Leaf (g/plant)	Stem (g/plant)	Ear (g/plant)	Grain (g/plant)	Leaf (g/plant)	Stem (g/plant)	Ear (g/plant)	Grain (g/plant)
688	PASPN	0.173 a	1.164 a	0.150 bc	0.311 b	0.010 d	0.447 c	0.012 d	3.138 a
	N0	0.114 b	1.104 a	0.212 a	0.243 c	0.027 c	0.450 c	0.047 c	2.501 c
	N180	0.084 c	0.983 b	0.239 a	0.418 a	0.071 a	0.421 c	0.068 bc	2.982 c
	S180	0.066 c	0.838 b	0.130 c	0.334 b	0.048 b	0.392 c	0.066 bc	3.009 b
	SU3	0.074 c	1.062 a	0.152 bc	0.423 a	0.009 d	0.734 ab	0.007 d	3.016 b
	SU5	0.029 c	0.965 b	0.060 d	0.307 b	0.008 d	0.828 ab	0.046 c	2.793 c
	SU7	0.059 c	1.406 a	0.166 bc	0.331 b	0.018 d	0.551 b	0.071 a	3.005 b
JF2	PASPN	0.019 b	1.198 c	0.086 b	0.360 b	0.035 d	0.487 b	0.012 d	3.002 a
	N0	0.023 a	1.144 c	0.020 c	0.250 c	0.022 d	0.502 a	0.008 d	2.351 c
	N180	0.011 b	1.295 b	0.012 c	0.375 b	0.066 bc	0.402 c	0.106 d	2.830 b
	S180	0.019 b	1.287 b	0.002 d	0.409 a	0.054 c	0.449 c	0.102 d	2.690 b
	SU3	0.007 c	1.255 bc	0.065 b	0.288 c	0.089 a	0.478 b	0.095 a	2.723 b
	SU5	0.019 b	1.322 a	0.077 b	0.302 bc	0.058 c	0.326 d	0.082 b	2.727 b
	SU7	0.021 a	0.900 d	0.121 a	0.320 b	0.076 b	0.453 c	0.077 c	2.855 b

Different lowercase letters mean significant difference at 0.05 level, while values with the same letter mean insignificant difference.

Table 4. Effects of different fertilization treatments on Nitrogen uptake and yield

Cultivar	Treatment	Grain N uptake kg/hm^2	Plant N uptake kg/hm^2
XY688	PASPN	3.14 a	4.05 b
	N0	2.48 c	3.45 c
	N180	3 b	4.19 ab
	S180	2.98 b	4.03 b
	SU3	3.03 ab	4.31 a
	SU5	2.76 b	4.08 ab
	SU7	2.97 b	3.96 b
JF2	PASPN	3.16 a	4.05 a
	N0	2.3 c	3.37 b
	N180	2.92 b	3.98 a
	S180	2.81 b	3.97 a
	SU3	2.83 b	3.91 a
	SU5	2.79 b	3.78 a
	SU7	2.87 b	3.89 a

Table 5. Effects of different fertilization treatments on nitrogen utilization and harvest index

Cultivar	Treatment	Nitrogen absorption efficiency Kg/kg	Nitrogen efficiency %	Partial factor productivity Kg/kg	Nitrogen harvest index %
XY688	PASPN	0.34 b	42.84 a	57.02 a	0.78 a
	N0	0.29 c	39.59 a	49.89 c	0.72 b
	N180	0.35 ab	39.76 a	51.30 c	0.72 b
	S180	0.34 b	40.91 a	53.80 bc	0.74 b
	SU3	0.36 a	40.70 a	54.28 b	0.70 b
	SU5	0.34 ab	40.19 a	53.37 bc	0.68 b
	SU7	0.33 b	44.95 a	56.83 ab	0.75 b
JF2	PASPN	0.338 a	41.57 a	51.47 a	0.78 a
	N0	0.281 b	37.49 b	47.10 c	0.69 c
	N180	0.332 a	39.90 a	48.42 b	0.73 b
	S180	0.331 a	40.57 a	48.75 b	0.71 bc
	SU3	0.326 a	40.79 a	49.17 b	0.72 bc
	SU5	0.315 a	41.85 a	47.86 b	0.74 b
	SU7	0.333 a	40.76 a	48.99 b	0.72 bc

Figure 2. Effects of different fertilization ratio on nitrate reductase concentration in Maize (a and b) and Effect of different fertilization ratio on the concentration of ALT in Maize (c and d)

Figure 3. Effect of different fertilization ratio on the concentration of ALT in Maize (a and b); and Effects of different fertilization ratio on GLNS concentration in Maize (c and d)