Effect of nitrogen application rate on its fate in “wheat-soil” under different fertility soil conditions

doi:10.21203/rs.3.rs-4672694/v1

Download PDF

Research Article

Effect of nitrogen application rate on its fate in “wheat-soil” under different fertility soil conditions

https://doi.org/10.21203/rs.3.rs-4672694/v1

This work is licensed under a CC BY 4.0 License

Version 1

posted

You are reading this latest preprint version

In order to study the nitrogen application rate in farmland with different fertility levels and the main destination and wheat absorption of N-fertilizer, to improve nitrogen use efficiency, three soils with different fertility levels were selected: chernozems soils (CS)、fluvo-aquic soils (FS) and rougi-limestone soils (RS), were used to study the effects of soil and nitrogen application rate on nitrogen fate of “wheat-soil” under the same ecological environment by isotope tracer technique in this experiment. The results showed that grain yield and nitrogen absorption of wheat in CS which with high fertility and nutrient content were significantly higher than that in FS and RS. Nitrogen fertilizer has a greater impact on the nitrogen content of FS and RS than on black soil. The ability of wheat to utilize residual fertilizer nitrogen in soil is less affected by the amount of nitrogen applied in the last season and is more affected by soil conditions, as CS > FS > RS. After planting two-season wheat, the proportion of nitrogen recovered by the wheat-soil is 37–68%, of which the nitrogen fixed by the soil accounts for 13–32% of the applied nitrogen. The average nitrogen loss of CS is 77.4 kg N·ha^− 1, that of FS is 102.9 kg N·ha^− 1 and that of RS is 153.1 kg N·ha^− 1, indicating that the CS condition is conducive to the absorption of N-fertilizer by wheat, with the least nitrogen loss and the least impact on the environment. When nitrogen application rate from 120 kg·ha^− 1 increased to 360 kg·ha^− 1, the nitrogen loss rate increased by 6.58 percentage points, but the nitrogen loss increased from 51.5 kg·ha^− 1 to 178.2 kg·ha^− 1, and the impact on the environment increased significantly. Therefore, we should pay attention to improve soil fertility and structure, and select the appropriate amount of nitrogen according to the actual situation of soil, so as to realize the synergistic improvement of wheat yield and nitrogen utilization, reduce resource consumption and the impact of nitrogen fertilizer on the environment in wheat production.

wheat

soil fertility

nitrogen application rate

nitrogen utilization

nitrogen loss

Soil is an important agricultural production factor, and its influence on crop growth is as important as climatic factors. Wheat (Triticum aestivum L.) is a nitrogen-loving crop, and approximately two-thirds of the nitrogen absorbed comes from the soil. Different soils and environments have different effects on nitrogen absorption by wheat. The effects of soil fertility and texture on strong gluten wheat yield were significantly different, and the wheat yield in high fertility soil was higher than that in medium fertility soil [Wu and Cui, 2004]. The studies have shown that the development of high-quality wheat should select medium soil or sticky plots with higher fertility and balanced nutrition [Du, 2003]. Dong et al. (2010) showed that there are different ways of increasing wheat yield in aquic cinnamon soil and rougi-limestone soils. In aquic cinnamon soil, increasing phosphorus fertilizer and increasing spike number are the main ways. In rougi-limestone soils, increasing organic fertilizer and increasing the grain number per spike are the main ways. Zhao et al. (2004) also studied the relationship between eight types of soils in Henan Province and strong gluten wheat yield. Their results showed that under the same natural climatic conditions, the relationship between wheat yield and soil type is small, and the soil fertility and total nitrogen content had significant effects on wheat yield, while available nitrogen and total nitrogen content had significant effects on the nitrogen absorption by wheat.

Nitrogen plays an important role in wheat yield formation. Since the characteristics of soil nitrogen supply are not completely consistent with the nitrogen demand law of wheat, reasonable application of nitrogen fertilizer can not only supplement and regulate the soil nitrogen supply, but can also meet the nitrogen demand of wheat and promote the plants' absorption of soil nitrogen. The utilization rate of N-fertilizer in China is low, about 30%-35%, the high input is the main reason for the low utilization efficiency[Li et al.,2020]. The extensive use of chemical fertilizers is not only wastes resources, but also poses a threat to the ecological environment. The studies have shown that nitrogen application significantly increased dry matter accumulation, translocation and wheat yield [Shi et al.,2004; Li et al.,2003]. In the range of 168–240 kg·ha^− 1, the nitrogen application rate could affect the absorption ratio of wheat to nitrogen from different sources. With the increase of nitrogen application rate, the total nitrogen accumulation of wheat had no significant difference, but the absorption ratio of soil nitrogen decreased and the absorption ratio of fertilizer nitrogen increased [Chen et al., 1986].

On the other hand, the nutrient cycle and balance in farmland system are also important factors reflecting the productivity of farmland [Wang, 2002]. Studying the distribution and balance of nitrogen fertilizer in the soil-crop system can provide theoretical basis for rational fertilization and practical guidance for agricultural production.

In order to increase wheat yield, it is necessary to pay attention to the utilization of nutrients after application and its impact on soil fertility. On the basis of saving resources and protecting the ecological environment, the potential of farmland soil production should be further developed. Adjusting farmland nutrient cycle and balance by reasonable fertilization is the main way to improve soil fertility [Ji et al., 2010].

Restricted by experiment scope and conditions, the above studies mostly focused on the effect of soil type (texture) with similar fertility or nitrogen application rate (nitrogen fertilizer type) under similar soil conditions on wheat growth and nitrogen utilization, and the results were different, which might be related to the planting conditions in which the experiment was conducted. In the case of large differences in soil conditions, the planting conditions is also very different, and the research results are difficult to distinguish whether it is caused by the ecological environment or soil. In the same planting conditions, there are relatively few studies on the effects of different properties soils and nitrogen fertilizer application on wheat nitrogen absorption and soil nitrogen change by high-precision synchronous isotopic technique.

Therefore, on the basis of previous studies, chernozems soils (CS), fluvo-aquic soils (FS) and rougi-limestone soils (RS) were selected as the test soils in our experiment at the same site (the planting conditions were exactly the same), and nitrogen application rate (¹⁵N as N-source) was used as control measures to study the effects of soils on the wheat nitrogen absorption as well as the direction of nitrogen application in soil, and explore the effects of soil and nitrogen application rate on nitrogen distribution and utilization in the “wheat-soil” system. Our results will provide a theoretical and technical reference for the farmland soil improvement and application of nitrogen fertilizer, improvement of nitrogen utilization in wheat and reduction of environmental pollution.

1.1 Sites and growing conditions

The experiment was carried out at the Beijing Experimental Base of the Chinese Academy of Agricultural Sciences from 2016 to 2018. The climate is a warm temperate semi-humid continental monsoon climate, with hot and rainy summers, cold and dry winters, and dry springs. The annual average temperature is 10–12℃, and the annual precipitation is generally between 400 and 800 mm. Attached figure shows the average daily temperature and daily precipitation during the test period.

1.2 Experimental design and treatments

The experiment is a pot experiment (the original natural state of soil structure has been destroyed, only the soil fertility is the biggest difference), the area of flowerpots was 0.04 m², and the soil mass was 7.5 kg per pot. The experiment was carried out in Beijing for two years. The sowing date was 13 October of each year, and the harvest date was 30 May. The random block experimental design was used. Factor A was the soil, and three soils (CS, FS, RS) were selected; Factor B was the nitrogen application, and the three treatments N120, N240, and N360 represent 120 kg·ha^− 1, 240 kg·ha^− 1, and 360 kg·ha^− 1(Actual using amount exists), respectively. ¹⁵N urea was used as the nitrogen source (N%=46%, ¹⁵N abundance = 10.12%), base fertilizer and topdressing accounted for 50% respectively, and topdressing fertilizer at the elongation stage, with three replicates. The experiment mainly studied the distribution and utilization of nitrogen fertilizer in wheat-soil in different years.

The main management measures included: uniform application of P₂O₅ at 0.69 g and K₂O at 0.45 g per pot in all experiments, leaving 8 seedlings/pot, measure every two days in spring to ensure that the relative soil moisture content is about 70% by watering in time(ensure that there is no water leakage from the bottom of the basin, and the nitrogen leaching loss can be ignored). After the wheat was harvested, no other crops were planted in the pots.

The tested cultivars were the strong gluten wheat cultivars Gaoyou 2018 and Shiluan 02 − 1. The tested soils are chernozems soils、fluvo-aquic soils and rougi-limestone soils with significant differences in fertility, taken from Heilongjiang, Beijing, and Yunnan, respectively. Soil nutrients and mechanical composition are in attached table.

1.3 Test content and methods

After wheat mature, all samples were harvested, separated into the grains, plants (stems and leaves), roots, and soil, dried at 70°C, and crushed through an 80-mesh sieve. The nitrogen contents of the samples were determined with Kjeltec 8100 of FOSS Company, and the ¹⁵N abundance in the sample was determined using a ZHT-03 mass spectrometer. Biological yield and grain yield are the actual harvest volume per pot.

Calculation of the nitrogen use efficiency:

¹⁵N utilization rate (%) = ¹⁵N accumulation (plant)/¹⁵N application×100

¹⁵N soil residual rate (%) = ¹⁵N accumulation (soil) /¹⁵N application×100

¹⁵N loss rate (%) = 100-¹⁵N utilization rate-¹⁵N soil residual rate

This experiment is a pot experiment, nitrogen leaching loss is negligible. The main ways of loss are ammonia volatilization and denitrification loss. Because results of the two tested cultivars were very similar, the data in this paper are the average values of the two cultivars.

1.4 Data analysis

Signifcance was determined by the least signifcant difference test, and a P–value

< 0.05 was considered signifcant. All were performed using SPSS 17.0. Data was processed using Microsoft Excel 2013. The graphics were drawn using Microsoft Excel 2013.

2.1 Effects of Different Soils and Nitrogen Application Rates on Wheat Grain Yield and Nitrogen Absorption

Comprehensive analysis of Figure 1, the yields of wheat grown in CS and FS are significantly higher than that in RS (Fig. 1A), with increases of 23.18 g and 12.70 g in the first season and 21.36 g and 11.86 g in the second season per pot, respectively. Under different soil conditions, with increasing nitrogen application rate, wheat grain yield increased first and then decreased in season, with N240 being the highest, which was significantly higher than N120 and N360. In the second year, there was no significant difference in yield among treatments because of no continuous application of nitrogen fertilizer.

The nitrogen content of the grains was the highest from plants grown in RS (Fig. 1B), and was 0.04、0.11 and 0.07、0.19 percentage points higher than that of CS and FS in two years, respectively. Under different soil conditions, in the first season, with the increase in nitrogen application rate, grain nitrogen content increased significantly and the N360 treatment was the highest, and there was significant difference among treatments. However, there was no significant difference among the treatments in the second year.

Nitrogen absorption was affected by both yield and nitrogen content. The wheat planted in chernozems soils had the highest N absorption (Fig. 1B ), which was higher than 53.7 % and 260.9 %, 56.4 % and 281.2 % of the wheat planted in FS and RS, respectively, in the two years, and the difference was significant. In the first year, N240 and N360 were significantly higher than N120, but there was no significant difference in the second year.

First year, the grain yield of CS + N240 was the highest, which was not significantly different from the N360 treatment, and was significantly higher than other treatments. The highest nitrogen absorption of grain was CS + N360, which was not significantly difference N240, and was significantly higher than that of other treatments. The grain nitrogen content was the highest in RS when the nitrogen application rate was 360 kg·ha^-1, which was significantly higher than other treatments, however, in this case the wheat grain yield was lower, which was only higher than the N120 treatment in RS. In general, chernozems soils combined with the 240 kg·ha^-1nitrogen fertilizer had the best effect, which could not only obtain the highest yield and nitrogen absorption, but also ensure higher nitrogen content in grain.

In conclusion, under the experimental conditions, planting wheat in chernozems soils with high nutrient content was conducive to improve wheat yield and nitrogen absorption, and the effect of soil on wheat yield and nitrogen content has little annual difference. The nitrogen application of 240 kg·ha^-1could simultaneously increase the grain yield and nitrogen absorption of wheat in the first season, but the nitrogen application rate had no effect on the grain yield and nitrogen content of wheat in the second season, and there was no significant difference among the treatments. Therefore, without fertilization, the higher the soil fertility and nitrogen content, the more beneficial to improve wheat grain yield and nitrogen absorption. The grain yield, nitrogen content and nitrogen absorption of wheat in the second season were lower than those in the first year, mainly due to the absence of nitrogen fertilizer.

2.2 Distribution and utilization of nitrogen in "wheat-soil" in current season

Table 2 shows that the interaction combinations of different soils and nitrogen application rates had significant effects on NDFF (the proportion of nitrogen from fertilizer) in wheat and soil. For all nitrogen application treatments in chernozems soils, NDFF of different parts of wheat was stem and leaf>root>grain; in fluvo-aquic soils, N120 and N240 showed as stem and leaf ＞ root ＞ grain, N360 was stem and leaf ＞ grain＞ root; and in RS, all N treatments were stem and leaf ＞ grain ＞ root. When the nitrogen application rate was increased from N120 to N240 and then to N360, the NDFF in wheat grains grown in CS increased 9.44 and 5.03 percentage points, 11.39 and 7.04 percentage points in FS, and 11.22 and 7.89 percentage points in RS, respectively. The changes in the NDFF of stem and leaf show similar patterns with the grain. It indicated that compared with CS, wheat was more likely to absorb fertilizer nitrogen in RS and FS.

The differences of soil NDFF among the treatments were significant, with the highest in FS + N360, followed by RS + N360, while the soil NDFF of FS + N240 and red soil + N240 were significantly higher than the CS + N360 treatment, indicating that the effect of nitrogen fertilizer on the nitrogen composition in the FS and RS was greater than that in CS, because the nitrogen content of CS was much higher than that of FS and RS.

Table 2. Effects of different soils and nitrogen application rates on NDFF (%) of wheat and soil

Treatments		Wheat			Soil
Treatments		Grain	Stem and leaf	Root	Soil
Black soil	N120	28.42 g	41.44 f	29.73 d	0.58 i
	N240	37.86 f	45.80 e	40.33 c	1.30 g
	N360	42.89 e	50.69 d	49.71 b	2.22 e
FS	N120	36.46 f	48.90 de	39.21 c	1.51 f
	N240	47.85 d	59.13 c	49.04 b	3.00 c
	N360	54.89 b	69.62 a	53.56 a	3.94 a
RS	N120	41.92 e	50.22 d	37.57 c	1.17 h
	N240	53.14 c	61.26 bc	49.47 b	2.37 d
	N360	61.03 a	64.54 b	48.52 b	3.48 b
average	CS	36.39 c	45.98 b	39.92 c	1.37 c
	FS	46.4 b	59.21 a	47.27 a	2.82 a
	RS	52.03 a	58.67 a	45.19 b	2.34 b
	N120	35.60 c	46.85 c	35.50 c	1.09 c
	N240	46.28 b	55.40 b	46.28 b	2.23 b
	N360	52.94 a	61.62 a	50.60 a	3.21 a

方差分析 Analysis of variance

Soil type(S)	117.92**	16.65*	NS	29.30**
Nitrogen(N)	143.75**	16.31*	22.35*	60.55**
S×N	18.70**	13.59**	15.59**	132.13**

The average values of soil and nitrogen application rate in table 2 showed that the NDFF of wheat organs (grain, stem and leaf, and root) and soil were significantly different under different soil conditions. The grain NDFF was highest in RS, followed by FS, and the lowest in black soil (compared with FS and RS, a decrease of 15.64 and 10.01 percentage points respectively), the difference was significant among treatments. The stem and leaf NDFF was the highest in FS, there was no significant difference between FS and RS and were significantly higher than that in CS (compared with FS and RS, a decrease of 12.7 and 13.24 percentage points, respectively). The NDFF of soil and root both showed the order FS>RS>CS, and the differences were significant among treatments. Compared with FS and RS, CS decreased of 0.98 and 1.45 percentage points, root in CS decreased by 5.27 and 7.35 percentage points respectively. In short, the NDFF of wheat organs and soil were the lowest in chernozems soils.

With the increase of nitrogen application rate, the NDFF of wheat and soil increased significantly. When the nitrogen application rate increased from 120 to 240 kg·ha^-1, the NDFF of grain, stem and leaf, root and soil increased by 10.68, 8.55, 10.78 and 1.14 percentage points respectively. When the nitrogen application rate increased from 240 to 360 kg·ha^-1, NDFF of grain, stem and leaf, root and soil increased by 6.66, 6.22, 4.32, 0.98 percentage points, respectively, indicating that wheat preferred to use nitrogen in fertilizer.

Table 3. Effects of different soil and nitrogen application rate on the distribution ratios of nitrogen fertilizer in the current season (%)

Treatments		Wheat			Soil residue	Loss
Treatments		Grain	Stem and leaf	Root	Soil residue	Loss
CS	N120	45.73 a	8.58 a	2.35 a	27.68 c	15.65 e
	N240	33.38 c	6.46 b	1.82 c	32.27 b	26.06 d
	N360	25.49 d	6.06 b	1.36 ef	38.51 a	28.58 cd
FS	N120	39.14 b	4.96 c	2.11 b	22.78 ef	31.01 c
	N240	28.02 d	4.79 c	1.66 cd	24.29 de	41.24 b
	N360	20.52 e	4.49 c	1.34 ef	25.92 cd	47.73 b
RS	N120	15.92 f	2.67 d	1.44 de	21.26 f	58.71 a
	N240	14.08 f	2.60 d	1.13 f	22.89 ef	59.30 a
	N360	11.03 g	1.95 e	0.75 g	24.62 de	61.64 a
Average	CS	34.87 a	7.04 a	1.84 a	32.82 a	23.43 c
	FS	29.23 b	4.75 b	1.70 b	24.33 b	39.99 b
	RS	13.68 c	2.41 c	1.11 c	22.92 c	59.88 a
	N120	33.60 a	5.40 a	1.97 a	23.91 c	35.12 c
	N240	25.16 b	4.62 b	1.54 b	26.48 b	42.20 b
	N360	19.01 c	4.17 c	1.15 c	29.68 a	45.99 a

方差分析 Analysis of variance

Soil type(S)	19.45*	36.61**	66.10**	17.69*
Nitrogen(N)	8.66*	NS	73.16**	NS
S×N	60.27**	27.71**	3.21*	20.96**

It is generally accepted that there are three main destinations after nitrogen fertilizer is applied to soil: one is absorbed by crops; second, residues in soil in different forms; third, losses from the soil-crop system through different mechanisms and pathways [Liu et al., 2010].

Table 3 showed that for the chernozems soils, the effect of nitrogen application rate on nitrogen distribution in grain and root was significantly different among treatments. The ratio of nitrogen distribution in stem and leaf of the N120 treatment was significantly higher than that of the N240 and N360 treatments, and there was no significant difference between the latter two. For the fluvo-aquic soils, the nitrogen accumulation in wheat grain and root were significantly different among nitrogen treatments, but there was no significant difference in stem and leaf nitrogen accumulation. For the rougi-limestone soils, there were no significant difference in grain nitrogen content and the stem and leaf nitrogen content between the N120 and N240 treatment, which were significantly higher than that in N360 treatment. The differences in root nitrogen distribution were significant among the three nitrogen treatments.

With the increase in nitrogen application rate, both the fixed and retained nitrogen in the soil and the nitrogen loss showed an increasing trend. For the chernozems soils, the differences in soil residual nitrogen among the three nitrogen treatments were significant; for the alluvial and rougi-limestone soils, except for the significant difference between the N360 and N120 treatments, the differences between adjacent nitrogen treatments was not significant. The nitrogen loss was similar in CS and FS, all showed that the loss of N120 was significantly lower than that of the N240 and N360 treatments, and the differences between the latter two were not significant. The nitrogen distribution ratio in different organs of wheat was the highest in CS + N120, and the lowest in RS +N360 treatment, while the nitrogen loss ratio was the opposite. The fixed ratio of soil to nitrogen fertilizer was the highest in CS + N360 treatment and the lowest in RS + N120 treatment.

The average values of soil and nitrogen application rates showed that wheat (include grain, stem and leaf, and root) planted in CS had the highest absorption of fertilizer nitrogen and the residual nitrogen in the soil, which were significantly higher than that in FS and RS, but the nitrogen loss was significantly lower than that in FS and RS. Compared with FS and RS, CS increased the nitrogen absorption rate of wheat by 8.07 and 26.55 percentage points, increased soil nitrogen retention by 8.49 and 9.9 percentage points, and reduced nitrogen loss by 16.56 and 36.45 percentages points. Therefore, chernozems soils can significantly improve the absorption and utilization of fertilizer nitrogen by wheat and the fixed retention of fertilizer nitrogen by soil, and correspondingly reduce the nitrogen loss.

With the increase of nitrogen application rate, the proportion of nitrogen distribution in wheat decreased significantly, and the proportion of residual nitrogen in soil and nitrogen loss increased significantly. When the nitrogen application rate increased from 120 kg·ha^-1to 360 kg·ha^-1, the proportion in the wheat grains, stem and leaf, roots decreased by 14.59, 1.23 and 0.82percentage points respectively. The proportion of residual nitrogen in soil increased by only 5.77 percentage points, but the total amount of residual nitrogen per hectare (pure nitrogen) increased from 28.69 kg to 106.85 kg. At the same time, the nitrogen loss increased from 42.14 kg to 165.56 kg, increased by about 3-fold, which increases environmental pollution.

2.3 Distribution and utilization of residual nitrogen fertilizer in "wheat-soil"

Table 4 showed that the effect of soil on the last season's nitrogen distribution was significant. The ratio of residual nitrogen absorbed by wheat grains in the last season to its own nitrogen content showed as RS> FS >CS; the ratio of residual nitrogen in the soil after the second year harvest to the soil nitrogen content showed as FS > RS >CS, and the difference reaches a significant level. The stem and leaf are the highest in FS, which is not significantly different from the RS, but both are significantly higher than the CS. The ratio of residual nitrogen absorbed by grains and the stem and leaf in the last season to its own nitrogen contents, and the ratio of residual nitrogen in the soil after the second year harvest to the soil nitrogen content all increased significantly with the increase of nitrogen application rate. The wheat has a relatively low absorption of residual nitrogen from the previous season, with an average of 3.41% for grains and 0.61% for stem and leaf. After the second year of harvest, the absorption and utilization of residual nitrogen by wheat grains and the stem and leaf and the amount of nitrogen remaining in the soil in the second year were the highest in FS, which were 4.21%, 0.77%, 82.92%, respectively, which was significantly higher than those in CS and RS. Wheat grains and stem and leaf had the lowest absorption of residual nitrogen fertilizer from the last season on the RS, but the CS had the lowest soil retention ratio, which indicating that FS was more conducive to the utilization of nitrogen for the second wheat. With the increase of nitrogen application rate in the last season, the proportion of wheat grains that absorbed the last season's residual nitrogen gradually

Table 4. Effects of different soil and nitrogen application rates on distribution and utilization of residual nitrogen fertilizer in previous season decreased, and the nitrogen retention in the soil was still significantly increased, in the stem and leaf is higher in N240, which is significantly higher than N120 and N360.

Treatments

Percentage of

own nitrogen content

Percentage of residual nitrogen in soil in the previous season

Percentage of total pure nitrogen applied in the previous season

Grain

Stalk

Soil

Grain

Stalk

Soil

Grain

Stalk

Soil

N120

0.84 i

1.27 f

0.27 i

3.85 b

0.71 b

45.85 f

1.07 bc

0.20 bc

12.84 h

N240

1.79 g

1.75 e

0.97 g

3.60 bc

0.60 cd

73.03 d

1.14 b

0.19 c

23.65 b

N360

2.91 d

2.30 d

1.84 e

3.22 c

0.56 de

81.85 b

1.24 a

0.22 ab

31.53 a

N120

1.27 h

2.10 d

1.17 f

4.60 a

0.66 bc

76.23 c

1.04 c

0.15 d

17.38 f

N240

2.70 e

3.23 c

2.58 c

4.43 a

0.81 a

85.60 a

1.08 bc

0.20 abc

20.79 d

N360

3.58 b

4.40 a

3.48 a

3.59 bc

0.85 a

86.92 a

0.92 d

0.22 a

22.53 bc

N120

1.96 f

2.24 d

0.83 h

2.72 d

0.41 f

70.47 e

0.58 e

0.09 f

14.98 g

N240

3.36 c

3.47 c

1.98 d

2.51 de

0.50 e

82.03 b

0.55 e

0.11 e

18.82 e

N360

4.34 a

3.84 b

3.04 b

2.17 e

0.35 f

86.21 a

0.54 e

0.09 f

21.24 cd

average

1.85 c

1.77 b

1.02 c

3.56 b

0.63 b

66.91 c

1.15 a

0.20 a

22.67 a

2.52 b

3.24 a

2.41 a

4.21 a

0.77 a

82.92 a

1.01 b

0.19 a

20.23 b

3.22 a

3.18 a

1.95 b

2.47 c

0.42 c

79.57 b

0.56 c

0.09 b

18.35 c

N120

1.36 c

1.87 c

0.76 c

3.73 a

0.59 b

64.18 c

0.90 a

0.14 b

15.07 c

N240

2.62 b

2.82 b

1.84 b

3.51 a

0.64 a

80.22 b

0.92 a

0.17 a

21.08 b

N360

3.61 a

3.51 a

2.79 a

3.00 b

0.59 b

84.99 a

0.90 a

0.17 a

25.10 a

方差分析 Analysis of variance

Soil type(S)	75.22**	16.65*	29.30**	90.65**	10.18*	NS	NS	23.33*	NS
Nitrogen(N)	204.28**	16.31*	60.55**	14.44*	NS	NS	33.63**	NS	NS
S×N	14.00**	13.59**	132.13**	NS	15.21**	106.11**	12.77**	8.83**	63.68**

Note：The nitrogen fertilizer treatment in the table is the treatment of the previous year.

From the analysis of the ratio of the residual nitrogen absorbed by the wheat in the second year and the residual nitrogen in the soil after two years to the total nitrogen applied, it can be concluded that the CS conditions are most conducive to the absorption of nitrogen by wheat and the retention of nitrogen in the soil, the FS was second, and RS was the least. The amount of nitrogen applied in the previous season had little effect on the nitrogen absorbed by wheat in the second year, but it still had a significant effect on soil residual nitrogen after the second year’s harvest. After the three fertilization treatments were absorbed and utilized by two season’s wheat, the residual pure nitrogen in soil per hectare was 18.1 kg, 50.6 kg, and 90.4 kg, respectively, with significant differences.

From the analysis of the residual nitrogen utilization ratio in the previous year (Table 4), by applying 120 kg·ha^-1nitrogen fertilizer (N120) to fluvo-aquic soils, the second season wheat had the highest utilization of nitrogen fertilizer, although it was not significantly different from the N240 treatment but was significantly higher than in the other treatment combinations. The N360 treatment had the lowest effect in rougi-limestone soils. The analysis of the second-season wheat's absorption ratio of nitrogen fertilizer showed that the proportion of wheat grains and the stem and leaf in CS + N360 was the highest, and the proportion of soil residues in the total fertilization was also the highest. After the second growing season, the fertilizer nitrogen loss ratio accounted for 8.6-49.6% of the last season's residual nitrogen, with an average of 19.5%.

2.4 Effects of soil and nitrogen application rate on nitrogen recovery and loss in the wheat-soil

Comprehensive nitrogen recovery and loss of “wheat-soil” in two years (Figure 2) showed that the utilization and recovery ratio of fertilizer nitrogen was the highest in CS and the lowest in RS, and the difference was significant. The difference between grains was 21.78%, and the difference between “wheat-soil” was 31.57%. Comparing the total loss in the wheat-soil, we can concluded that the average loss of nitrogen in CS was 77.4 kg, that in FS was 102.9 kg, and in RS the loss was as high as 153.1 kg. The results showed that the chernozems soils conditions were conducive to the absorption and utilization of nitrogen fertilizer by wheat, has the least nitrogen loss and the least impact on the environment; Rougi-limestone soils has the highest nitrogen loss and has the greatest impact on the environment.

With the increases in the nitrogen application rate, the nitrogen recovery and utilization rate decreased significantly for both the grain and the wheat-soil system. In the wheat-soil system, when the nitrogen application rate increased from 120 kg·ha^-1 to 360 kg·ha^-1, the nitrogen loss rate increased from 42.92% to 49.5% after two years, although the ratio only increased by 6.58% percentage points, the nitrogen loss increased from 51.5 kg to 178.2 kg per hectare, the absolute loss increased by more than 3-fold, and the degree of environmental pollution increased significantly. Therefore, according to specific soil conditions, proper and reasonable application of nitrogen fertilizer is not only conducive to high-quality, high-yielding crops, but also more conducive to saving resources and protecting the ecological environment.

Previous studies have shown that the effects of different soils on the nutrient accumulation of winter wheat decreased as an order: chernozem soil, forest soil, podzol soil, and soils with different salinities[Lixandru, 1962], the yield of spring wheat was as follows: sandy loamy chernozems soils > leached chernozem > meadow chernozem [Perkovic and Kovacevic-tatic, 1966]. The soil texture affects soil moisture and nutrients to a large extent, so they have different nutrient supply capabilities [Zhang et al., 2015]. Studies by Si et al. (2007) and Qi et al.(2021) have shown fluvo-aquic soils, mortar chernozems soils, and yellow cinnamon soil have large differences in basic fertility, texture, and pH, and thus have different effects on wheat growth. Fluvo-aquic soils is more conducive to wheat growth. The yield of wheat grown in limestone soil and chernozem soil varies with the N level, and the optimal nitrogen application rate was 120 kg·ha^− 1[Che, 2011]. The proportion of soil nitrogen accumulated by wheat high fertility soil was higher than that in low fertility soil [Zhang et al., 2007]. This experiment showed that the grain yield of wheat grown in CS and FS with high fertility were significantly higher than that in RS. The absolute amount of nitrogen absorption of wheat was the highest in CS, and it is significantly higher than that in FS and RS, and was 2.6-fold higher than in RS. It is mainly because the content of organic matter and available nitrogen in CS is high, which promotes the absorption and utilization of nitrogen by wheat, and has little relationship with soil mechanical composition, CS was more conducive to the absorption of nitrogen by the grains. Other researchers have also obtained the same results [Ma et al., 2006; Ye et al., 2010]. The grain nitrogen content in RS was significantly higher than that in CS and FS, because the yield of wheat planted in red soil was the lowest, which increased the grain nitrogen content relatively.

There are few reports on nitrogen loss after nitrogen application in different soils under the same ecological conditions. This experiment showed that chernozems soils could improve the absorption of fertilizer nitrogen by wheat in the current season, increase the nitrogen retention in soil, and significantly reduce nitrogen loss compared with FS and RS. In addition, the effect of nitrogen application on the composition of nitrogen in FS and RS was greater than that on CS, it is mainly because of the nitrogen content in CS was much higher than that in FS and RS and the effect of nitrogen application was weakened. Therefore, planting wheat in the soil (CS) with higher basic fertility was more conducive to improving wheat yield and nitrogen use efficiency.

A large number of studies have shown that the application of nitrogen fertilizer can effectively increase yield and the nitrogen content of wheat grains [Ma et al., 2010; Johansson and Maria luisa, 2001; Cheng et al., 2010; Jiang et al., 2009]. Compared with basal fertilizer, wheat has a much stronger absorption of topdressing, and the amount of nitrogen absorbed increases rapidly with increasing plant growth [Chen et al., 1986]. Compared with soil and grain recovery, the recovery rate of stem (including root) was low. Wang et al.[Wang et al., 2003] have shown that the utilization rates of nitrogen fertilizer for both basal and topdressing applications in wheat was higher in high-fertility soils than that of low-fertility soils, while the soil residual rate and loss rate were higher in low-fertility soils than that in high-fertility soils. The same results were obtained in this study, with the increase of the nitrogen application rate, wheat yield increased first and then decreased, and grain nitrogen absorption increased significantly, with 240 kg·ha^− 1 N as the highest. Nitrogen application rate had significant effect on the proportion of nitrogen derived from fertilizers in the wheat and soil. The isotope tracing results showed that wheat preferentially uses fertilizer nitrogen, with the doubling of nitrogen application rate, the proportion of fertilizer nitrogen in the wheat to its own nitrogen content also increased significantly, and N360 and N240 increased by 5.77% and 2.57% compared with the N120 treatment, respectively. Other researchers have reached the same conclusion under different experimental conditions [Zhao and Yu, 2006]. The main reason is that the level of soil fertility or soil nitrogen supply capacity restricts the absorption and utilization of nitrogen by wheat and the efficiency of nitrogen fertilizer.

The utilization of fertilizer by crops is not only related to crop yield, but also has an important impact on resource utilization and environmental pollution. Zhang et al.[Zhang, 2019] found that when the nitrogen application rate was in the range of 75 kg·ha^− 1~150 kg·ha^− 1, the residual nitrogen in soil increased with the increase of nitrogen application rate, but the loss rate changed little. When the nitrogen application rate was 300 kg·ha^− 1, the loss rate increases significantly. Also some scholars believe that with increasing nitrogen application rate, the soil residual rate was reduced [Shi et al., 2013]. The results showed that CS was more beneficial than FS and RS to improve the absorption and utilization of fertilizer nitrogen in wheat in the current season, and greatly reduce nitrogen loss (39.7 kg and 87.5 kg, respectively). With the increase of nitrogen application rate, the fixed nitrogen in soil and the nitrogen loss both showed an increasing trend. Compared with N120 treatment, the absorption and utilization of nitrogen by wheat in the current season were significantly reduced, under the condition of N240 and N360, and the nitrogen loss was significantly increased, which was 59.1 kg (N240) and 123.4 kg (N360), respectively, these results are in accord with the results of previous studies [Xu et al., 2010; Ottman and Pope, 2000]. Also, the increase in nitrogen loss will increase its impact on the farmland and atmosphere environment.

At present, there are few reports on the effect of nitrogen application rate on the utilization of residual nitrogen from the previous season in wheat in different soil conditions. This study showed that the utilization and recovery ratio of fertilizer nitrogen in CS was the highest, while RS was the lowest. With the increase of nitrogen application rate, the nitrogen recovery and utilization rate for both the grain and the wheat-soil were decreased significantly. With the increase of nitrogen application rate from 120 kg to 360 kg per hectare, the absolute loss of nitrogen increased by more than 3-fold, which greatly increased the risk of environmental pollution. Therefore, soil with high fertility (CS) is more conducive to the utilization and fixation of fertilizers, and reduces environmental pollution. Restricted by the experimental conditions, we need to further increase soil types, reduce the gradient of nitrogen application rate, and expand the scope of the experimental area for more in-depth research to explore mechanism of soil affecting nitrogen utilization in wheat and more accurate nitrogen application rate suitable for high yield and efficient nitrogen utilization of wheat under different soil conditions.

Chernozems soils with higher fertility and reasonable mechanical composition has the greatest effect on fertilizer nitrogen fixation, the lowest amount of nitrogen loss to the environment and the least impact on the environment. It can give higher yield, nitrogen absorption and nitrogen use efficiency.

Wheat grain yield and nitrogen absorption reached the maximum at 240 kg N·ha^− 1. After two growing seasons, with the rate of nitrogen application increased from 120 kg·ha^− 1 to 360 kg·ha^− 1, the absolute loss of nitrogen was significantly increased by more than 3-fold.

Therefore, we should focus on fertilizing soil and improving soil structure and other aspects, so as to realize the efficient utilization of nitrogen by wheat and reduce the loss of nitrogen fertilizer in production. However, only applying a large amount of nitrogen fertilizer is not conductive to the increase in wheat yield, but more importantly, it increases environmental pollution caused by the loss of nitrogen fertilizer.

AUTHOR CONTRIBUTIONS

Ma Ruiqi contributed to the experimental design, data analyses, and original draft preparation, Chang Xuhong contributed to the supervision, Wang Demei contributed to the data curation, investigation, and methodology, Wang Yanjie and Yang Yushuang helped with investigation, Tao Zhiqiang did the methodology and data curation, and Zhao Guangcai helped with funding acquisition, project administration, writing-review and editing.

G L Wu, X Z Cui. Effects of the yield and quality of strong gluten wheat under different Soil fertility and texture, Journal of Henan Vocation-Technical teachers College. 32(2004) 1-2.
C L Du. Study on the effect of different cultivation conditions on wheat grain quality and yield, Shandong Agricultural Sciences. 4(2003) 21-22. DOI:10.14083/j.issn.1001-4942.2003.04.005
L H Dong, Y Y Li, H C Pang, Q Q Sun. Comparison of the effect of long-term fertilizer application on soil nutrients and wheat yield under different soil types, Journal of China Agricultural University. 15(2010) 22-28.
S Z Zhao, S Q Ji, S Z Wang, F R Lv. The relationship between different types of soil and the quality and yield of strong gluten wheat, Henan Agricultural Sciences. 7(2004) 52-53. DOI:10.15933/j.cnki.1004-3268.2004.07.017
X X Li, Z L Shi, J C Wang, F Wang, R F Jiang. Effect of Nitrogen Application Nitrogen Uptake, Utilization and Translocation Winter Wheat in Rice-Wheat Rotation, Journal of Triticease Crops. (40)20201334-1341. DOI: 10.7606/j. ISSN. 1009. 2020.11.07.
Z L Shi, D X Gu, C H Zhang, J G Yu, S J Yang. Effects of nitrogen rates on vertical distribution of dry matter and nutrient of winter wheat in rice-wheat rotation, Journal of Triticease Crops. 34(2004) 114-119. http://www.cnki.net/kcms/doi/10.7606/j.issn.1009-1041.2014.01.19.html
Y M Li, C Q Du, C M Lin, X H Wang. The transformation of ammonium-nitrogen in the soil after fertilizer application, Journal of Yunnan Agricultural University. 18(2003) 26-29. DOI: 10.16211/j. ISSN. 1004-390x (n). 2003.01.006.
Y L Chen, Q G Zhang, Z X Liang, F J Wang, N Mei. Studies on the influence of the application of fertilizers at different growth stages on the nitrogen absorption and organ formation of winter wheat, Acta Agronomica Sinica. 12(1986) 101-108.
Y Wang. Preliminary study on nutrient’s cycle and balance in farmland soil of Heilongjiang Province, Chinese Journal of Soil Science. 33(2002) 268-271.
J H Ji, Y Y Li, S Q Liu, Y Liu, M Y Zhang, G Han, S C Sun. The effect of balanced fertilization on yield，benefit of corn and nutrient balance, Soils and Fertilizers Sciences in China. 4(2010) 37-41.
X Y Liu, X T Ju, L J Zhang, X Li, L J Yuan, N Liu. Effects of different N rates on fate of N fertilizer and balance of soil N of winter wheat, Plant Nutrition and Fertilizer Science. 16(2010) 296-303.
Lixandru, G. The accumulation of nutrients in the aerial parts of winter wheat grown on some soil types in northern Moldavia. (1962) 125-132.
Perkovic, M., Kovacevic-tatic, R. Results of several years investigations of ratios and quantities of NPK for wheat OH different soil types, Zemljiste I Biljka. 15 (1966) 311-322.
X Q Zhang, C F Cao, Y Q Qiao, S Z Du, Z Zhao. Effect of soil water content on photosynthesis and yield of wheat under different soil water content conditions, Acta Agriculturae Boreali-occidentalis Sinica. 24(2015) 44-50. Doi:10.7606/j.issn.1004-1389.2015.04.008
J Y Si, X L Wang, D M Chen, K Feng. Effects of NH₄⁺-N and NO₃^--N on crop seedling growth under different pH levels, Journal of Yangzhou University (Agricultural and Life Science Edition).28(2007) 68-71. DOI:10.16872/j.cnki.1671-4652.2007.03.01
X Qi, Y K Si, Y N Zhao, Y F Huang, J Y Yan, X M Sun, Y L Ye. Impacts of nitrogen forms on ntrogen utilization and yield of wheat in different types of soil, Journal of Agricultural Science and Technology. 23(2021) 172-181.
[17 J Y Che. Effect of soil fertility and soil moisture content of different soil types on spring wheat yield, Heilongjiang Agricultural Sciences. 3(2011) 41-44.
X Zhang, Y Q Luo, S Q Zhang, Y C Wu, M Wang, Z M Wang. Effect of different fertilization way on yield and protein content of winter wheat under water-saving cultivation system, Agricultural Research in the Arid Areas. 25(2007) 46-49.
X H Ma, Z W Yu, X F Liang, H Yan, G P Shi. Effects of Nitrogen application rate and ratio of base and topdressing on Nitrogen utilization and soil NO₃^- N Content in winter wheat, Journal of Soil and Water Conservation. 20(2006) 95-98.
Y L Ye, G L Wang, Y J Zhu, H H Li, Y F Huang. Effects of nitrogen fertilization on population dynamics and yield of high-yielding wheat and on alteration of soil nitrogen, Chinese Journal of Applied Ecology. 21(2010) 351-358. DOI:10.13287/j.1001-9332.2010.0022
S K Ma, G C Zhao, X H Chang, Y S Yang, G X Yang, F J Xu. The effects of nitrogen and chemical control on wheat quality, Acta Agriculture Boreali-sinica. 25(2010) 190-193.
Johansson E, Maria luisa P L. Effects of wheat cultivar and nitrogen application on storage protein composition and bread making quality, Soil and Plant Science. 78 (2001) 19-25, 414-418.
B Cheng, J Wang, Y C Yin, Y F Wang, J Z Du. Effects of nitrogen application on the contents and components of protein in wheat, Journal of Qingdao Agricultural University (Natural Science). 27(2010) 289-292.
H Z Jiang, B J Yan, F Q Tan, H Q Zhang, Z L Ren. Effect of different nitrogen fertilizer amount and application period on wheat quality, Journal of Triticeae Crops. 29(2009) 658-662.
Y F Wang, Z W Yu, S X Li, S L Yu. Effects of soil fertility and nitrogen application rate on nitrogen absorption and translocation, grain yield, and grain protein content of wheat, Chinese Journal of Applied Ecology. 14(2003) 1868-1872. DOI:10.13287/j.1001-9332.2003.0413
J Y Zhao, Z W Yu. Effects of nitrogen fertilizer rate on uptake, distribution and utilization of nitrogen in winter wheat under high yielding cultivated condition, Acta Agronomica Sinica. 32(2006) 484-490.
X Zhang. Nutrition mechanism and environmental effects of increasing wheat yield by low N input and plastic film mulching in dryland, NORTHWEST A&F UNIVERSITY. 2019.
Z L Shi, D X GU, C H Zhang, S J Yang, J G Yu, K J GU, S M Zhang. Research advances in nitrogen loss and high-efficient utilization in soil-crop system, Acta Agriculturae Jiangxi. 25(2013) 83-89. DOI:10.19386/j.cnki.jxnyxb.2013.10.023
Y Xu, Z H Liu, LH Jiang, H T Lin, F L Zheng, D S Tan. Effects of different nitrogen regulation on nitrogen fertilizer use of winter wheat and content of soil nitrate-N, Journal of Soil and Water Conservation. 24 (2010) 90-93, 98.
Ottman M J, Pope N V. Nitrogen fertilizer movement in the soil as influenced by nitrogen rate and timing in irrigated wheat, Soil Science Society of America Journal. 64(2000) 1883-1892.

Attached table: nutrient contents and the mechanical composition of the three different soil

Soil	Organic matter (g kg⁻¹)	Total N (g kg⁻¹)		Alkali-hydrolysis N (mg kg⁻¹)	Available P (P₂O₅mg kg⁻¹)	Available K (K₂O mg kg⁻¹)	pH	Mechanical composition（g/kg)
Soil	Organic matter (g kg⁻¹)	Total N (g kg⁻¹)		Alkali-hydrolysis N (mg kg⁻¹)	Available P (P₂O₅mg kg⁻¹)	Available K (K₂O mg kg⁻¹)	pH	＞ 0.2 mm Coarse sand	0.2-0.02 mm Fine sand	0.02-0.002 mm Powder	＜ 0.002 mm Cosmid
Black soil	58.66	3.32	276.92		38.12	228	7.8	30	210	410	350
Alluvial soil	17.35	0.89	122.36		13.43	98.0	8.1	180	610	100	110
Red clay	18.36	0.94	88.55		6.37	58	7.2	20	220	340	420

Download PDF

Version 1

posted

You are reading this latest preprint version

Effect of nitrogen application rate on its fate in “wheat-soil” under different fertility soil conditions

Status:

Version 1

Abstract

Figures

Introduction

1 Materials and methods

2 Results

3 Discussion

4 Conclusions

Declarations

AUTHOR CONTRIBUTIONS

References

Attached table

Status:

Version 1