Effects of planting density and nitrogen application on leaf enzyme activity and water-nitrogen utilization of silage maize under ridge furrow rainwater harvesting in Loess Plateau

doi:10.11686/cyxb2021315

Abstract

Abstract:

A field experiment was conducted in Huan County， Gansu Province， to explore the effects of planting density and nitrogen application levels on leaf enzyme activity and water-nitrogen use efficiency of silage maize （Zea mays） under ridge furrow rainwater harvesting. Four planting densities （D₁： 6×10⁴ plants·ha^-1； D₂： 7.5×10⁴ plants·ha^-1； D₃： 9.0×10⁴ plants·ha^-1； D₄： 10.5×10⁴ plants·ha^-1） and four nitrogen application levels （N₀： 0 kg·ha^-1； N₁： 120 kg·ha^-1； N₂： 240 kg·ha^-1； N₃： 360 kg·ha^-1） were included in the experiment. In summary， it was found： 1） The activities of nitrate reductase （NR）， superoxide dismutase （SOD） and catalase （CAT） decreased with increase in plant density. However， the NR， SOD and CAT activity increased with N application and at the grain filling stage were significantly higher under N₂ and N₃ treatments than in the N₀treatment. 2） The fresh and hay yield increased incrementally with increase in plant density. The average fresh and hay yield of the N₃ treatment was numerically highest， but the difference between N₃ and N₂ treatments was not statistically significant. 3） The precipitation utilization efficiency （PUE） and biomass water use efficiency （WUE_B） of D₃ and D₄ treatments were significantly higher than those of D₁ and D₂ treatments， and the grain yield water use efficiency （WUE_G） of D₃ treatment was greater compared to other treatments. Moreover， PUE， WUE_B and WUE_G of N₂ and N₃ treatments were significantly higher than those of N₀ and N₁ treatments. 4） The nitrogen content of D₃ and D₄ treatments was less than that of D₁ treatment， but the nitrogen uptake， nitrogen agronomic efficiency （AEN） and nitrogen use efficiency （NUE） of D₃ and D₄ treatment were significantly higher than those of treatment D₁. With increase in nitrogen application rate， nitrogen content and nitrogen uptake increased， while AEN and NUE initially increased and then decreased as nitrogen application rate increased. There was no significant interaction between planting density and nitrogen application rate for leaf enzyme and water-nitrogen use efficiency in our experiment. Among all the treatments， NUE， WUE_G and WUE_B were the highest in D₃-N₂ treatment， and higher yield was obtained. These results indicate that D₃-N₂ is a suitable agronomic management regime for silage maize production in the Loess Plateau.

Key words: ridge furrow rainwater harvesting, planting density, nitrogen application, enzyme activity, water use efficiency, nitrogen use efficiency

Da-liang ZHOU, Wei SHI, Zi-wei JIANG, Zheng-ye WEI, Huan-huan LIANG, Qian-min JIA. Effects of planting density and nitrogen application on leaf enzyme activity and water-nitrogen utilization of silage maize under ridge furrow rainwater harvesting in Loess Plateau[J]. Acta Prataculturae Sinica, 2022, 31(8): 126-143.

Figures/Tables 11

References 64

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种植密度 Planting density	施氮水平 Nitrogen application	吐丝期 Spinning period		灌浆期 Filling stage
种植密度 Planting density	施氮水平 Nitrogen application	2019	2020	2019	2020
D₁	N₀	80.9±6.37a	83.8±5.36ab	48.1±3.86abc	56.2±3.99abcd
	N₁	85.4±6.73a	84.4±5.93ab	49.5±4.14ab	61.2±4.49ab
	N₂	84.3±6.85a	88.6±5.90a	53.2±3.71a	63.3±5.33a
	N₃	83.9±6.05a	89.5±6.72a	53.7±4.75a	65.1±4.98a
D₂	N₀	80.7±4.94a	80.6±6.37ab	36.1±2.95defg	50.2±3.57bcde
	N₁	76.2±5.33a	81.9±5.04ab	39.8±2.91cdef	54.9±4.19abcd
	N₂	78.0±5.86a	85.4±7.33ab	44.0±3.83abcd	59.1±4.94abc
	N₃	80.6±7.79a	86.9±6.96ab	45.9±3.73abcd	58.8±5.75abc
D₃	N₀	71.7±5.70a	72.8±6.79ab	33.1±3.15efg	43.7±3.25def
	N₁	73.2±5.26a	73.5±6.69ab	36.6±2.79defg	49.0±3.67bcde
	N₂	75.3±6.92a	79.2±7.79ab	39.1±3.81cdef	53.0±5.33abcde
	N₃	77.0±7.55a	81.7±8.74ab	42.1±4.51bcde	53.7±5.73abcd
D₄	N₀	71.1±4.66a	68.8±4.79b	28.7±1.73g	36.4±2.77f
	N₁	70.4±5.94a	71.7±5.25ab	31.8±2.34fg	41.0±3.22ef
	N₂	75.1±7.01a	76.1±7.11ab	35.9±3.18defg	44.7±4.12def
	N₃	75.2±6.22a	77.3±6.48ab	39.1±3.45bcde	46.8±4.05cdef
平均值 Average	D₁	83.6±5.81A	86.6±5.73A	51.1±4.32A	61.5±5.33A
	D₂	78.9±5.54AB	83.7±6.14A	41.5±4.92B	55.8±5.50B
	D₃	74.3±5.87B	76.8±7.53B	37.7±4.65C	49.8±5.73C
	D₄	73.0±5.63B	73.5±6.23B	33.9±4.73D	42.2±5.14D
	N₀	76.1±6.76A	76.5±8.02B	36.5±7.93B	46.6±8.25B
	N₁	76.3±7.71A	77.9±7.48AB	39.4±7.24B	51.5±8.50A
	N₂	78.2±6.88A	82.3±7.92AB	43.1±7.51A	55.0±8.45A
	N₃	79.2±6.88A	83.8±7.92A	45.2±6.70A	56.1±8.30A
显著性 Significance	PD	**	**	**	**
	NA	ns	*	**	**
	PD×NA	ns	ns	ns	ns

种植密度 Planting density	施氮水平 Nitrogen application	吐丝期 Spinning period		灌浆期 Filling stage
种植密度 Planting density	施氮水平 Nitrogen application	2019	2020	2019	2020
D₁	N₀	80.9±6.37a	83.8±5.36ab	48.1±3.86abc	56.2±3.99abcd
	N₁	85.4±6.73a	84.4±5.93ab	49.5±4.14ab	61.2±4.49ab
	N₂	84.3±6.85a	88.6±5.90a	53.2±3.71a	63.3±5.33a
	N₃	83.9±6.05a	89.5±6.72a	53.7±4.75a	65.1±4.98a
D₂	N₀	80.7±4.94a	80.6±6.37ab	36.1±2.95defg	50.2±3.57bcde
	N₁	76.2±5.33a	81.9±5.04ab	39.8±2.91cdef	54.9±4.19abcd
	N₂	78.0±5.86a	85.4±7.33ab	44.0±3.83abcd	59.1±4.94abc
	N₃	80.6±7.79a	86.9±6.96ab	45.9±3.73abcd	58.8±5.75abc
D₃	N₀	71.7±5.70a	72.8±6.79ab	33.1±3.15efg	43.7±3.25def
	N₁	73.2±5.26a	73.5±6.69ab	36.6±2.79defg	49.0±3.67bcde
	N₂	75.3±6.92a	79.2±7.79ab	39.1±3.81cdef	53.0±5.33abcde
	N₃	77.0±7.55a	81.7±8.74ab	42.1±4.51bcde	53.7±5.73abcd
D₄	N₀	71.1±4.66a	68.8±4.79b	28.7±1.73g	36.4±2.77f
	N₁	70.4±5.94a	71.7±5.25ab	31.8±2.34fg	41.0±3.22ef
	N₂	75.1±7.01a	76.1±7.11ab	35.9±3.18defg	44.7±4.12def
	N₃	75.2±6.22a	77.3±6.48ab	39.1±3.45bcde	46.8±4.05cdef
平均值 Average	D₁	83.6±5.81A	86.6±5.73A	51.1±4.32A	61.5±5.33A
	D₂	78.9±5.54AB	83.7±6.14A	41.5±4.92B	55.8±5.50B
	D₃	74.3±5.87B	76.8±7.53B	37.7±4.65C	49.8±5.73C
	D₄	73.0±5.63B	73.5±6.23B	33.9±4.73D	42.2±5.14D
	N₀	76.1±6.76A	76.5±8.02B	36.5±7.93B	46.6±8.25B
	N₁	76.3±7.71A	77.9±7.48AB	39.4±7.24B	51.5±8.50A
	N₂	78.2±6.88A	82.3±7.92AB	43.1±7.51A	55.0±8.45A
	N₃	79.2±6.88A	83.8±7.92A	45.2±6.70A	56.1±8.30A
显著性 Significance	PD	**	**	**	**
	NA	ns	*	**	**
	PD×NA	ns	ns	ns	ns

种植密度 Planting density	施氮水平 Nitrogen application	吐丝期Spinning period		灌浆期Filling stage
种植密度 Planting density	施氮水平 Nitrogen application	2019	2020	2019	2020
D₁	N₀	791.9±57.30ab	652.7±41.70abc	596.4±44.60ab	511.8±38.15abcd
	N₁	797.7±53.28ab	672.5±43.29abc	612.4±43.52ab	558.2±42.53ab
	N₂	838.3±56.91a	708.8±51.45a	655.4±55.54a	577.1±47.15a
	N₃	847.4±77.34a	712.1±61.17a	660.5±49.42a	593.7±55.28a
D₂	N₀	759.8±49.51ab	626.2±39.15abc	459.1±35.35cde	457.0±35.55bcde
	N₁	773.4±60.36ab	645.2±51.37abc	501.6±36.66bcd	500.6±36.60abcd
	N₂	807.6±66.98ab	666.5±56.77abc	550.1±42.16abc	539.0±38.47abc
	N₃	821.6±72.34ab	683.1±66.67ab	571.7±58.25abc	536.2±45.24abc
D₃	N₀	684.3±52.12ab	558.1±43.46abc	424.5±35.50de	397.0±38.01def
	N₁	690.9±57.38ab	611.0±54.41abc	465.3±42.22cde	446.4±38.95bcde
	N₂	746.8±71.69ab	635.4±53.51abc	494.0±44.84bcde	482.5±41.71abcde
	N₃	770.9±80.99ab	655.4±67.07abc	528.1±48.40bcd	489.1±54.29abcde
D₄	N₀	644.2±46.38b	519.3±30.12c	375.0±23.68e	333.0±26.51f
	N₁	672.8±59.90ab	551.4±44.93bc	410.5±35.63de	375.4±27.44ef
	N₂	716.1±61.27ab	609.6±63.53abc	456.6±39.00cde	409.3±33.90def
	N₃	727.9±58.47ab	602.4±42.19abc	493.5±41.27bcde	428.5±41.48cdef
平均值 Average	D₁	818.8±58.61A	686.5±49.98A	631.2±50.31A	560.2±50.75A
	D₂	790.6±59.63A	655.2±51.55AB	520.6±59.11B	508.2±48.16B
	D₃	723.2±68.49B	615.0±60.53BC	478.0±54.09C	453.7±53.39C
	D₄	690.3±59.83B	570.7±55.65C	433.9±55.89D	386.6±47.17D
	N₀	720.1±75.41B	589.1±64.59B	463.7±91.09C	424.7±75.77B
	N₁	733.7±74.08AB	620.0±62.88AB	497.4±84.22BC	470.1±77.19A
	N₂	777.2±74.58AB	655.1±61.78A	539.0±87.53AB	502.0±74.53A
	N₃	792.0±78.55A	663.2±66.44A	563.5±77.83A	511.9±76.16A
显著性 Significance	PD	**	**	**	**
	NA	*	**	**	**
	PD×NA	ns	ns	ns	ns

种植密度 Planting density	施氮水平 Nitrogen application	吐丝期Spinning period		灌浆期Filling stage
种植密度 Planting density	施氮水平 Nitrogen application	2019	2020	2019	2020
D₁	N₀	791.9±57.30ab	652.7±41.70abc	596.4±44.60ab	511.8±38.15abcd
	N₁	797.7±53.28ab	672.5±43.29abc	612.4±43.52ab	558.2±42.53ab
	N₂	838.3±56.91a	708.8±51.45a	655.4±55.54a	577.1±47.15a
	N₃	847.4±77.34a	712.1±61.17a	660.5±49.42a	593.7±55.28a
D₂	N₀	759.8±49.51ab	626.2±39.15abc	459.1±35.35cde	457.0±35.55bcde
	N₁	773.4±60.36ab	645.2±51.37abc	501.6±36.66bcd	500.6±36.60abcd
	N₂	807.6±66.98ab	666.5±56.77abc	550.1±42.16abc	539.0±38.47abc
	N₃	821.6±72.34ab	683.1±66.67ab	571.7±58.25abc	536.2±45.24abc
D₃	N₀	684.3±52.12ab	558.1±43.46abc	424.5±35.50de	397.0±38.01def
	N₁	690.9±57.38ab	611.0±54.41abc	465.3±42.22cde	446.4±38.95bcde
	N₂	746.8±71.69ab	635.4±53.51abc	494.0±44.84bcde	482.5±41.71abcde
	N₃	770.9±80.99ab	655.4±67.07abc	528.1±48.40bcd	489.1±54.29abcde
D₄	N₀	644.2±46.38b	519.3±30.12c	375.0±23.68e	333.0±26.51f
	N₁	672.8±59.90ab	551.4±44.93bc	410.5±35.63de	375.4±27.44ef
	N₂	716.1±61.27ab	609.6±63.53abc	456.6±39.00cde	409.3±33.90def
	N₃	727.9±58.47ab	602.4±42.19abc	493.5±41.27bcde	428.5±41.48cdef
平均值 Average	D₁	818.8±58.61A	686.5±49.98A	631.2±50.31A	560.2±50.75A
	D₂	790.6±59.63A	655.2±51.55AB	520.6±59.11B	508.2±48.16B
	D₃	723.2±68.49B	615.0±60.53BC	478.0±54.09C	453.7±53.39C
	D₄	690.3±59.83B	570.7±55.65C	433.9±55.89D	386.6±47.17D
	N₀	720.1±75.41B	589.1±64.59B	463.7±91.09C	424.7±75.77B
	N₁	733.7±74.08AB	620.0±62.88AB	497.4±84.22BC	470.1±77.19A
	N₂	777.2±74.58AB	655.1±61.78A	539.0±87.53AB	502.0±74.53A
	N₃	792.0±78.55A	663.2±66.44A	563.5±77.83A	511.9±76.16A
显著性 Significance	PD	**	**	**	**
	NA	*	**	**	**
	PD×NA	ns	ns	ns	ns

种植密度 Planting density	施氮水平 Nitrogen application	吐丝期Spinning period		灌浆期 Filling stage
种植密度 Planting density	施氮水平 Nitrogen application	2019	2020	2019	2020
D₁	N₀	10.60±0.67abc	10.10±0.74abcd	9.22±0.69abcd	8.78±0.58abc
	N₁	11.16±0.90ab	11.11±0.90ab	9.51±0.80abc	9.59±0.66abc
	N₂	11.71±0.89a	11.52±0.91ab	10.30±0.81ab	10.35±0.92a
	N₃	11.64±0.92a	11.89±0.90a	10.39±0.75a	10.64±0.83a
D₂	N₀	7.95±0.50defg	8.90±0.56cdefg	6.71±0.53efg	8.03±0.55bcd
	N₁	8.48±0.57defg	9.85±0.67abcde	7.49±0.60cdefg	8.87±0.62abc
	N₂	9.72±0.67abcde	10.69±0.89abc	8.37±0.69bcdef	9.55±0.87abc
	N₃	9.94±0.95abcd	10.63±1.03abc	8.77±0.78abcd	9.83±0.97ab
D₃	N₀	7.19±0.60fg	7.59±0.58fg	6.73±0.58efg	6.66±0.55de
	N₁	7.68±0.72efg	8.67±0.72cdefg	7.48±0.66cdefg	7.54±0.60cde
	N₂	8.83±0.75cdef	9.46±0.86bcdef	8.01±0.83cdef	8.60±0.73abcd
	N₃	9.46±0.97bcde	9.60±1.04bcdef	8.64±0.97abcde	9.09±1.06abc
D₄	N₀	6.48±0.37g	6.12±0.42h	5.82±0.43g	5.97±0.41e
	N₁	7.04±0.55fg	7.05±0.61gh	6.48±0.58fg	6.62±0.50de
	N₂	7.84±0.78efg	7.79±0.69efgh	7.32±0.69defg	7.63±0.67cde
	N₃	8.49±0.66defg	8.21±0.64defgh	8.00±0.77cdef	7.91±0.72bcde
平均值 Average	D₁	11.28±0.86A	11.15±1.02A	9.85±0.84A	9.84±0.99A
	D₂	9.02±1.05B	10.02±1.03B	7.84±1.00B	9.07±0.98B
	D₃	8.29±1.15C	8.83±1.09C	7.72±0.99B	7.97±1.18C
	D₄	7.46±0.95D	7.29±0.97D	6.91±1.02C	7.03±0.96D
	N₀	8.05±1.69B	8.18±1.63C	7.12±1.41B	7.36±1.24C
	N₁	8.59±1.74B	9.17±1.68B	7.74±1.28B	8.16±1.31B
	N₂	9.53±1.63A	9.87±1.63AB	8.50±1.32A	9.03±1.27A
	N₃	9.88±1.41A	10.08±1.61A	8.95±1.16A	9.37±1.30A
显著性 Significance	PD	**	**	**	**
	NA	**	**	**	**
	PD×NA	ns	ns	ns	ns