Introduction
The
shortage of water resources is an important factor limiting the sustainable
development of agriculture in arid and semi-arid areas, and it promotes the
degradation of cultivated land, which is the main reason for the imbalance of
soil ecological balance and the decline of productivity (Wei et al. 2019). As an important
conservation tillage measure, subsoiling has good ecological and economic
effects (Li et al. 2011; He et al. 2018). The outline of northeast
black soil protection plan (20172030) issued in June 2017 pointed out that deep
subsoiling and deep ploughing should be promoted in dry farming areas of
Northeast Plain to enhance the sustainability of farmland system in black soil
area to consolidate and enhance the comprehensive agricultural production
capacity.
Traditional shallow rotary tillage makes the topsoil
shallower, the bottom of the plow thickens, and the
soil's ability to conserve water and soil moisture decreases, and soil erosion
is serious. As a result, the farmland ecological environment continues to
deteriorate, seriously affecting agricultural production and crop yield (Wang et al. 2000; Ghosh et al. 2005; Zhao et al.
2014). Studies have shown that deep pine can effectively break the bottom of
the plough, reduce surface runoff, increase precipitation infiltration, promote
the circulation of soil gas, improve drought-resistant and moisture retention
ability of soil (Han et al. 2009;
Ingrid et al. 2012; Wang et al. 2019). Deep pine can improve soil
structure, increase soil porosity, promote root growth and binding, and improve
root uptake of soil water and nutrients (Baumhardt et al. 2008; Qi et al. 2012; Ping et al. 2020).
Deep pine can also promote the growth of crops, increase the accumulation of
dry matter, and improve grain yield and water use efficiency of crops (He et al. 2006; Xie
et al. 2020).
Previous research on
subsoiling has made more progress. Zhang et
al. (2020) studied soil physical and chemical properties of spring maize
under subsoiling rotation tillage, showing that it could improve soil
structural stability and fertility. Wang et
al. (2019) reported that that the effect of subsoiling in summer on soil
bulk density was better than in autumn, and the soil nutrient content of
subsoiling in autumn was higher than in summer. Liu et al. (2020) studied the period and mode of subsoiling, which
showed that lateral subsoiling was more conducive to summer maize root system
absorbing soil nutrients. Kaur and Arora (2019) studied the nitrogen absorption
and yield under subsoiling, which indicated that it was helpful to solve the
limitation of drought on nitrogen absorption and maize yield. Schneider et al. (2017) studied the crop yield
under subsoiling, and showed that the effects of subsoiling on crop yield in
different regions were different due to the differences of soil types and
climate. Therefore, subsoiling is an effective measure to improve soil
productivity.
In view of the lack of water resources, soil plough
bottom thickening and plough layer structure degradation caused by long-term
mechanized operation. The effects of subsoiling on soil structure, crop growth,
material accumulation and water use was studied.
Materials
and Methods
Survey
of experimental field
The
experiment was conducted in Taonan comprehensive experimental
base (45°20' N, 122°49' E, 156.8 m a.s.l) of Jilin
Academy of Agricultural Sciences from 2011 to 2016. The base is located in the
western edge of Songnen Plain, with continental
monsoon climate in North Temperate Zone. It is dry in spring with little wind
and rain, hot and concentrated rainfall in summer, moderate cold and warm in
autumn, severe cold and little snow in winter. The annual average sunshine
duration is 3005.3 h, the average annual solar radiation is 532.2 J / cm2,
the average annual evaporation is 2083.3 mm, the active accumulated temperature
≥ 10°C is 2910°C, and the annual frost-free period is 142 days. The soil
type is light chernozem. The specific nutrient composition of soil is shown in
Table 1.
During the maize planting period, seasonal drought
occurred in May, July and September of 2015 and May, August and September of
2016 (Fig. 1). The annual precipitation was 476.8 mm in 2015, including 394 mm
from May to September, and 371.6 mm in 2016, including 325.7 mm from May to
September (Fig. 1). The maize was irrigated three times with 30 mm irrigation
each time in 2015 and 2016.
Experimental
design
Since
2011, subsoiling has been carried out once every two years. In this study, the
data of the cycle from 2015 to 2016 are used research. Mechanical subsoiling
was carried out before sowing in spring and after harvesting in autumn in 2015.
Five treatments were set up: 30 cm subsoiling before
sowing in spring (SS-30), 40 cm subsoiling (SS-40) before sowing in spring, 30
cm between rows after autumn harvest (AS-30), 40 cm between rows after autumn harvest
(AS-40), and no subsoiling (CK). Xianyu 335 was
selected as the test maize variety. The sowing density was 60000 plants / hm2.
The fertilization rate was 213 kg / hm2 of pure nitrogen, 75 kg / hm2
of P2O5 and 75 kg / hm2 of K2O.
35% nitrogen fertilizer and all phosphorus and potassium fertilizer were
applied before sowing, and the remaining 65% nitrogen fertilizer was applied at
jointing stage.
Determination
of soil properties
The
total nitrogen, phosphorus, potassium, hydrolyzeable
nitrogen, available phosphorus and potassium, organic matter and pH value of 060
cm soil layer were measured before sowing in 2015. The total nitrogen content
was determined by H2SO4 digestion Kjeldahl
nitrogen determination method, the total phosphorus content was determined by
concentrated H2SO4-HClO4 digestion molybdenum
antimony resistance colorimetry method, and the total potassium content was
determined by NaOH melting flame photometer method. Determination of hydrolyzed
nitrogen content by Alkali Solution Diffusion, determination of available
phosphorus content by molybdenum antimony colorimetric method, ammonium acetate
extraction flame photometric method was used to determine the content of
available potassium, determination of soil organic matter by potassium dichromate
oxidation-external heat method (Bao 2000). Soil pH was measured by METTLER
TOLEDO 320 using the soil water ratio was 1:2.5.
The bulk density of 040 cm soil layer was measured by
ring knife method, and soil compactness was measured by JC-JSD-01 soil
compactness tester after harvesting in autumn of 2015 and 2016. The moisture
content of 0100 cm soil was measured by drying method at different growth
stages of maize in 2016.
TTC
reduction amount and root activity were determined by TTC reduction method (Zou
1997). The absorption area of the root was measured by colorimetry according to
the change of the concentration of the test solution. It is known that the area
of 1 mg methylene blue as a single molecular layer is 1.1 m2. Based
on this, the total and active absorption area of root Table 1: The soil nutrient composition in the experimental field
|
Measure the depth (cm) |
Total N
(g/kg) |
Total P
(g/kg) |
Total K
(g/kg) |
Hydrolytic N (mg/kg) |
Available P (mg/kg) |
Available
K (mg/kg) |
Organic
matter (g/kg) |
pH |
|
0-20 |
1.039 |
0.506 |
24.335 |
64.456 |
18.035 |
83.829 |
24.335 |
7.77 |
|
20-40 |
0.977 |
0.420 |
23.787 |
58.606 |
15.225 |
69.637 |
23.787 |
7.92 |
|
40-60 |
0.886 |
0.253 |
22.380 |
43.709 |
5.071 |
46.399 |
23.430 |
8.13 |
%20751-760_files/image002.png)
Fig.
1: Precipitation in the experiment area in 2015 and 2016
system can be calculated. The calculation formula is
as follows:
Root activity (g / g / h) = TTC reduction (g) / root
weight (g) × time (h)
Total absorption area (m2) = [(C1 - C1ˊ) × V1] + [(C2 - C2ˊ) × V2] × 1.1
Active absorption area (m2) = [(C3 - C3ˊ) × V3] × 1.1
The
ratio surface = the absorption area of the root / the volume of the root
The C is the original concentration of solution mg/mL,
Cˊ concentration after extraction mg/mL, V root volume ml, 1, 2, 3
beaker number.
The stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate (Tr) and net photosynthetic
rate (Pn)
of ear leaves were measured by LC Pro+ automatic portable photosynthesis
instrument at silking stage, at 9 a.m. to 11 a.m., and the light intensity was
set at 1700 μmol/m2/s (Zhu et al. 2011). The leaf water use
efficiency (WUE) was calculated according to the formula: leaf WUE = Pn/Tr.
Determination of total aboveground dry
weight and root dry weight in 040 cm soil. The fresh samples were put into
the drying oven, sterilized at 105°C for 30 min, dried at 80°C to constant dry
weight, and the root-shoot ratio was determined. The water balance method was
used to calculate the farmland water consumption (ET) and WUE per plant. According
to the formula: ET = precipitation in growth period + irrigation water + (soil
water before sowing - soil water at harvest) (Zhai et al. 2016), WUE per plant =
above-ground biological yield/ET.
All ears within 20 m2 were collected and
weighed at the harvest time of maize. According to the average single ear
weight, 20 even ears were selected and air-dried, and the number of grains per
ear and the weight of 100 grains were measured, then the yield (14% water
content in grain) and population WUE were calculated, according to the formula:
population WUE = Yield/ET.
Statistical
analysis
Analysis
of variance was conducted to determine the effect of subsoiling on soil and
maize. Differences between means were distinguished through the least
significant difference (LSD) test at 0.05 confidence level. The experimental
data were processed and analyzed by Excel 2013 and DPS 15.10 software.
Results
Effects of subsoiling on soil
properties
%20751-760_files/image004.png)
Fig. 2:
Comparison of soil compactness in 2015 (A) and 2016 (B). In the figure, different
lowercase letters indicate significant differences in the level of P < 0.05. The same below
Soil
penetration resistance, also known as soil compactness, is an indicator of soil
strength. In 2015, the compactness of subsoiling treatment in 030 cm soil
layer was significantly lower than CK. In 010 cm soil layer the compactness of
AS-40 was significantly lower than of AS-30, SS-40 and SS-30. In 1020 cm soil
layer the compactness of AS-30 and AS-40 was significantly lower than SS-30 and
SS-40. In 2030 cm soil layer, the compactness of SS-40 and AS-40 was
significantly lower than of AS-30 and SS-30. The compactness of AS-40 and SS-40
in 3040 cm soil layer was significantly lower than in AS-30, SS-30 and CK, and
the compactness of AS-40 was significantly lower than SS-40 (Fig. 2A).
In 2016, the compactness of subsoiling treatment in 030
cm soil layer was significantly lower than CK. In 010 cm and 1020 cm soil
layer the compactness of AS-30 was significantly lower than SS-40, SS-30 and
AS-40. In 2030 cm soil layer the compactness of SS-40 and AS-40 was
significantly lower than of AS-30 and SS-30. The compactness of SS-40 and AS-40
in 3040 cm soil layer was significantly lower than SS-30, AS-30 and CK, and
the compactness of SS-40 was significantly lower than AS-40 (Fig. 2B).
In 2015, the bulk density of subsoiling treatment in 030
cm soil layer is significantly lower than CK. In 020 cm soil layer the bulk
density of AS-30 and AS-40 was significantly lower than of SS-40 and SS-30, and
the bulk density of AS-30 was significantly lower than of AS-40, the bulk
density of SS-40 was significantly lower than of SS-30 (Fig. 3A). In 2030 cm
soil layer the bulk density of SS-40 and AS-40 was significantly lower than of
AS-30 and SS-30 (Fig. 3A). The bulk density of AS-40 and SS-40 in 3040 cm soil
layer was significantly lower than AS-30, SS-30 and CK, and the bulk density of
AS-40 was significantly lower than SS-40 (Fig. 3A).
In 2016, the bulk density of subsoiling treatment in 030
cm soil layer was significantly lower than of CK. In 010 cm soil layer the
bulk density of AS-40 and SS-40 was significantly lower than in SS-30 and
AS-30. In 1030 cm soil layer the bulk density of SS-30 and AS-30 was
significantly lower than of AS-40 and SS-40, and SS-30 was significantly lower
than of AS-30 (Fig. 3B). In 3040 cm soil layer the bulk density of AS-40 and
SS-40 was significantly lower than of AS-30 and SS-30, and the bulk density of
AS-40 was significantly lower than of SS-40 (Fig. 3B).
The soil moisture content of each treatment was
relatively high at sowing time. The soil moisture content of AS-30 and AS-40 in
2040 cm soil layer was significantly higher than of SS-30, SS-40 and CK. In 4060
cm and 6080 cm soil layers %20751-760_files/image006.png)
Fig.
3: Comparison of soil bulk density in 2015 (A) and 2016
(B)
the soil moisture content was significantly higher than
of CK (Fig. 4A). At seedling stage, soil moisture content of AS-30, AS-40 and
SS-40 in 020 cm soil layer was significantly higher than of SS-30 and CK (Fig.
4B), the soil moisture content of 2040 cm soil layer subsoiling treatment was
significantly higher than of CK. The soil moisture content of SS-40 and AS-40
in 4060 cm soil layer was significantly higher than of SS-30, AS-30 and CK. At
jointing stage, the soil moisture content of subsoiling treatment in 080 cm
soil layer was significantly higher than CK and there was a maximum difference
between the soil moisture content of subsoiling treatment in 2040 cm soil
layer and of CK (Fig. 4C). At silking stage, the soil
moisture content of subsoiling treatment in 0100 cm soil layer was
significantly higher than of CK, in 2040 cm soil layer the soil moisture
content of AS-40 and AS-30 was significantly higher than of SS-40 and SS-30,
the soil moisture content of AS-40 was significantly higher than of AS-30 (Fig.
4D). During the filling stage, the soil moisture content of subsoiling treatment in 040 cm soil layer was
significantly higher than of CK, the soil moisture content of AS-40 and SS-40
in 4080 cm soil layer was significantly higher than of AS-30, SS-30 and CK (Fig.
4E). The soil moisture content of SS-40, SS-30 and AS-30 in 020 cm soil layer
was significantly higher than CK at maturity stage, and that of subsoiling
treatment in 2080 cm soil layer was significantly higher than of CK (Fig. 4F).
Effect of subsoiling on root
activity
Maize
roots in the soil layer of 040 cm were dug at silking stage, and the activity
indexes of the roots were measured by methylene blue colorimetric method and
TTC reduction method. The total and active absorption area in maize roots of
subsoiling treatment was significantly higher than those in CK (Fig. 5). The
total absorption area of SS-40 and SS-30 roots was significantly higher than of
AS-30 and AS-40 in 2015, and the active absorption area of SS-40 and SS-30 were
significantly higher than of AS-30 and AS-40. The total and active absorption
area of AS-40 were significantly higher than of SS-40, and that of AS-30 and
SS-30 were significantly higher than of SS-30 in 2016. The total and active
absorption area of AS-40 roots were significantly higher than of SS-40, while
of AS-30 and SS-30 roots were significantly higher than of SS-30 in 2016.
The active absorption area / total absorption area ratio
of SS-40 and SS-30 in 2015 was significantly higher than of AS-30, AS-40 and
CK, and the ratio of AS-40 and SS-40 in 2016 was significantly higher than of
AS-30, SS-30 and CK (Table 2). The total specific surface area, active specific
surface area, TTC reduction amount and root activity of subsoiling treatment
were significantly higher than those of CK in 2015 and 2016. The active
specific surface area of SS-40, SS-30, AS-40 and AS-30 were 3.44, 2.47, 0.26
and -0.03% were higher than CK in 2015, and the root activity was 21.95 17.74, 8.99
and 5.80% higher than of CK, respectively. The active specific surface area of
AS-40, SS-40, AS-30 and SS-30 were 2.47, 1.85, 1.32 and 0.62% higher than those
of CK in 2016, and the root activity were 20.37, 18.23, 7.83 and 5.92% higher
than CK, respectively.
Effects of subsoiling on leaf
photosynthetic characteristics
Table
2: Comparison of root activity indices of maize
|
Year |
Treatments |
Actively
absorption surface/Total absorption surface (%) |
Total
specific surface (cm2/mL) |
Active
specific surface (cm2/mL) |
Reductive
amount of TTC by root (μg) |
Root
vigor (μg/g/h) |
|
2015 |
SS-30 |
32.74 b |
12.64 b |
11.63 b |
37.97 b |
75.94 b |
|
|
SS-40 |
33.18 a |
12.70 a |
11.74 a |
39.33 a |
78.66 a |
|
|
AS-30 |
32.01 c |
12.54 d |
11.35 d |
34.12 d |
68.24 d |
|
|
AS-40 |
31.96 d |
12.58 c |
11.38 c |
35.15 c |
70.30 c |
|
|
CK |
31.86 e |
12.52 e |
11.35 d |
32.25 e |
64.50 e |
|
2016 |
SS-30 |
31.85 d |
12.35 d |
11.42 d |
34.63 d |
69.25 d |
|
|
SS-40 |
32.89 a |
12.48 b |
11.56 b |
38.65 b |
77.30 b |
|
|
AS-30 |
32.28 c |
12.42 c |
11.50 c |
35.25 c |
70.50 c |
|
|
AS-40 |
32.87 a |
12.53 a |
11.63 a |
39.35 a |
78.70 a |
|
|
CK |
32.37 b |
12.29 e |
11.35 e |
32.69 e |
65.38 e |
Table
3: Comparison of photosynthetic indices and WUE of maize leaves
|
Year |
Treatments |
Ci |
Tr |
Gs |
Pn |
WUE |
|
(μmol/mol) |
(mmol/m2 s-1) |
(mol/m2 s-1) |
(μmol/m2 s-1) |
(μmol/mmol) |
||
|
2015 |
SS-30 |
121.4 b |
5.91 b |
0.43 b |
45.6 b |
7.71 a |
|
SS-40 |
133.2 a |
6.16 a |
0.44 a |
47.6 a |
7.73 a |
|
|
AS-30 |
112.8 d |
5.25 d |
0.40 d |
38.6 d |
7.35 c |
|
|
AS-40 |
118.6 c |
5.66 c |
0.41 c |
42.8 c |
7.57 b |
|
|
CK |
110.2 e |
5.11 e |
0.39 e |
37.3 e |
7.30 c |
|
|
2016 |
SS-30 |
109.1 b |
5.12 d |
0.39 c |
38.0 c |
7.43 c |
|
SS-40 |
114.3 b |
5.58 c |
0.41 b |
42.7 b |
7.65 b |
|
|
AS-30 |
118.2 ab |
5.78 b |
0.43 a |
44.7 a |
7.73 a |
|
|
AS-40 |
126.4 a |
6.02 a |
0.44 a |
46.6 a |
7.75 a |
|
|
CK |
109.3 b |
5.07 e |
0.39 c |
37.6 c |
7.41
c |
Table
3: Comparison of photosynthetic indices and WUE of maize leaves
|
Year |
Treatments |
Ci |
Tr |
Gs |
Pn |
WUE |
|
(μmol/mol) |
(mmol/m2 s-1) |
(mol/m2 s-1) |
(μmol/m2 s-1) |
(μmol/mmol) |
||
|
2015 |
SS-30 |
121.4 b |
5.91 b |
0.43 b |
45.6 b |
7.71 a |
|
SS-40 |
133.2 a |
6.16 a |
0.44 a |
47.6 a |
7.73 a |
|
|
AS-30 |
112.8 d |
5.25 d |
0.40 d |
38.6 d |
7.35 c |
|
|
AS-40 |
118.6 c |
5.66 c |
0.41 c |
42.8 c |
7.57 b |
|
|
CK |
110.2 e |
5.11 e |
0.39 e |
37.3 e |
7.30 c |
|
|
2016 |
SS-30 |
109.1 b |
5.12 d |
0.39 c |
38.0 c |
7.43 c |
|
SS-40 |
114.3 b |
5.58 c |
0.41 b |
42.7 b |
7.65 b |
|
|
AS-30 |
118.2 ab |
5.78 b |
0.43 a |
44.7 a |
7.73 a |
|
|
AS-40 |
126.4 a |
6.02 a |
0.44 a |
46.6 a |
7.75 a |
|
|
CK |
109.3 b |
5.07 e |
0.39 c |
37.6 c |
7.42
c |
Table
4: Comparison of root-cap ratio and WUE of each treatment
|
Year |
Treatments |
Total dry weight (g) |
Root dry weight (g) |
Root-shoot ratio (%) |
WUE per plant
(g/mm) |
|
2015 |
SS-30 |
237.3 b |
21.32 b |
8.98 d |
0.49 b |
|
SS-40 |
254.1 a |
21.57 a |
8.49 e |
0.52 a |
|
|
AS-30 |
208.6 d |
20.91 d |
10.02 b |
0.43 d |
|
|
AS-40 |
224.5 c |
21.24 c |
9.46 c |
0.46 c |
|
|
CK |
193.5 e |
20.73 e |
10.71 a |
0.40 e |
|
|
2016 |
SS-30 |
198.8 c |
20.63 b |
10.38 b |
0.47 c |
|
SS-40 |
225.1 b |
20.81 ab |
9.25 c |
0.54 b |
|
|
AS-30 |
226.4 b |
20.91 ab |
9.24 c |
0.54 b |
|
|
AS-40 |
248.8 a |
20.96 a |
8.43 d |
0.59 a |
|
|
CK |
188.6 d |
20.29 c |
10.76 a |
0.45 d |
The Ci,
Tr, Gs and Pn of subsoiling
treatments in 2015 were significantly higher than CK, in which SS-40 and SS-30 were
significantly higher than AS-40 and AS-30, and SS-40 was significantly higher
than of SS-30 (Table 3). The WUE of SS-40, SS-30 and AS-40 was significantly
higher than of AS-30 and CK, among which, the WUE of SS-40 and SS-30 was
significantly higher than AS-40 and AS-30, and of SS-40 was significantly
higher than of SS-30. The WUE of SS-40, SS-30, AS-40 and AS-30 leaves were
5.62, 5.89, 0.68 and 3.70% higher than CK, respectively. In 2016 the Ci, Tr, Gs
and Pn
of subsoiling treatment were higher than CK, in which the Tr, Gs
and Pn
of AS-40, AS-30 and SS-40 were significantly higher than those of SS-30 and CK,
and the Ci, Tr, Gs and Pn of AS-40 were significantly higher than SS-40.
The WUE of subsoiling treatment was higher than of CK, in which AS-40, AS-30
and SS-40 was significantly higher than CK, and AS-40 and AS-30 was
significantly higher than SS-40 and SS-30. The WUE of SS-40, SS-30, AS-40 and
AS-30 was 0.27, 3.29, 4.32 and 4.59% higher than CK, respectively.
%20751-760_files/image010.png)
Effects of subsoiling on root-cap ratio and WUE per plant
Subsoiling
could affect dry matter accumulation, root shoot ratio and WUE per plant. The
total aboveground dry weight, 040 cm root dry weight and WUE per plant of
subsoiling treatment were significantly higher than CK, and the root-shoot
ratio of Table 5:
Comparison of yield components, yield and population WUE of maize
|
Year |
Treatments |
Kernels per ear |
100-kernel Weight (g) |
Yield (kg/hm2) |
Population WUE (kg/mm) |
|
2015 |
SS-30 |
652 a |
34.7 a |
12197.1 b |
25.20 b |
|
SS-40 |
651 a |
35.8 a |
12748.8 a |
26.34 a |
|
|
AS-30 |
646 a |
33.2 b |
11662.0 c |
24.10 c |
|
|
AS-40 |
646 a |
33.6 b |
11708.5 c |
24.19 c |
|
|
CK |
638 a |
32.9 b |
11585.2 c |
23.94 c |
|
|
2016 |
SS-30 |
598 cd |
30.2 d |
10528.3 c |
25.3 c |
|
SS-40 |
604 bc |
32.0 c |
10921.0 b |
26.3 b |
|
|
AS-30 |
612 b |
34.1 b |
11066.8 b |
26.6 b |
|
|
AS-40 |
628 a |
36.6 a |
11639.1 a |
28.0 a |
|
|
CK |
590 d |
29.6 d |
10332.1 c |
24.8 c |
%20751-760_files/image012.png)
Fig.
5: Comparison of total absorption area and active
absorption area of maize root
subsoiling
treatment was significantly lower than CK (Table 4). The total dry weight, root
dry weight and WUE per plant of SS-40 and SS-30 were significantly higher than
AS-40 and AS-30 in 2015, in which SS-40 were significantly higher than SS-30.
The root-shoot ratio of SS-40 and SS-30 was significantly lower than AS-40 and
AS-30, and the root-shoot ratio of SS-40 were significantly higher than SS-30.
WUE per plant of SS-40, SS-30, AS-40 and AS-30 was 22.5, 30.0, 7.5 and 15.0%
higher than CK, respectively. The aboveground total dry weight, 040 cm root dry
weight and WUE of per plant of AS-40 were significantly higher than AS-30,
SS-40 and SS-30 in 2016, among which, the aboveground total dry weight and WUE
of per plant of AS-30 were significantly higher than those of SS-30. The
root-shoot ratio of AS-40 was significantly lower than AS-30, SS-40 and SS-30,
among which the root-shoot ratios of AS-30 and SS-40 were significantly lower
than of SS-30. Per plant WUE of SS-40, SS-30, AS-40 and AS-30 was 4.4, 20.0,
20.0 and 31.1% higher than CK, respectively.
Effects of subsoiling on Yield
and WUE
Subsoiling
could affect maize yield and WUE. There was no significant difference in grain
number per spike between subsoiling and CK in 2015 (Table 5). The WUE of 100
grain weight, yield and population of subsoiling were higher than CK, in which
SS-40 and SS-30 were significantly higher than of AS-40, AS-30 and CK, and the
yield and population WUE of SS-40 were significantly higher than SS-30. The WUE
of SS-40, SS-30, AS-40 and AS-30 was 5.26, 10.03, 0.67 and 1.04% higher than
CK, respectively. The 100-grain weight, yield and population WUE of AS-40,
AS-30 and SS-40 were significantly higher than of SS-30 and CK in 2016, in
which AS-40 was significantly higher than of AS-30 and SS-40, and AS-30 was
significantly higher than of SS-30. The WUE of SS-40, SS-30, AS-40 and AS-30
was 2.02, 6.05, 7.26 and 12.9% higher than CK, respectively.
Discussion
The
present study found that subsoiling significantly reduced the soil penetration
resistance and bulk density, and significantly increased the soil water content
from subsoiling part to the surface, which was consistent with previous
research conclusions. It also found that compactness and bulk density of
subsoiling in 2015 were lower than in 2016.
Xu et al.
(2012) found that subsoiling can significantly reduce the soil compactness of
plough bottom and increase the soil moisture of plough layer. Liu et al. (2015) studied that subsoiling
can significantly reduce soil volume, increase soil water infiltration and
increase field water holding capacity. It is further confirmed that subsoiling
can effectively last for at least one growing season (Hamilton et al. 2019). In the range of subsoiling, the
soil water content of subsoiling in 2040 cm soil layer is significantly higher
than CK, which is basically consistent with the research results of Xiao et al. (2011). To conclude effect of
subsoiling on soil penetration resistance, bulk density and water content will
gradually decreases with time. Because the upper soil is greatly influenced by environmental
and mechanical operation, the effect of subsoiling on the upper soil is
weakened rapidly. Properly increasing the subsoiling depth can effectively improve
the soil regulation of subsoiling. In arid areas, subsoiling can improve soil
water storage and soil moisture conservation, delay water loss and enhance soil
drought resistance.
Qin et al.
(2008) and Zhang et al. (2015)
concluded that subsoiling can promote root depth distribution, retard root
senescence and improve root activity in soil. Holloway and Holloway (1991), Zhang et al. (2004) and Lv et al. (2019) concluded that subsoiling was beneficial to root
fixation and ligation, and could promote root absorption of water and nutrients
in soil. Based on previous studies, found that subsoiling can significantly
improve the total absorption area, active absorption area, total specific
surface area, active specific surface area and TTC reduction amount of maize
root system, and deeply analyzed the effect of subsoiling on the activity and
growth of maize root system. Based on the comparison of root activity indexes
in two years, it is considered that the promotion effect of subsoiling on root
activity will gradually weaken with the extension of interval time. Appropriate
increase of subsoiling depth can enhance root activity.
Feng et al.
(2015) considered that subsoiling could improve the photosynthetic leaf area of
maize and significantly increase the Pn of leaves in different layers. Jin et al. (2014) and Xie
et al. (2019) considered that subsoiling
was beneficial to improve SPDA value, LAI, net photosynthetic rate and leaf
area duration of maize leaves. Further experiments confirm that subsoiling can
not only increase Pn
but also increase Ci, Tr, Gs and leaf WUE. It is found that the influence of
subsoiling on Ci, Tr, Gs, Pn and leaf WUE will gradually weaken with time,
and the appropriate increase of subsoiling depth can delay the effect of
subsoiling.
Izumi et al. (2009)
considered that subsoiling has significant positive effects on biomass and
yield. Zheng et al. (2013) found that
subsoiling can improve the dry matter accumulation in wheat and promote the
distribution of photosynthates to grain. Cai
et al. (2014) and Guan et al.
(2014) concluded that subsoiling can regulate root growth and exudates, promote
soil nutrient uptake, increase biomass and grain yield. In this study, the
results showed that subsoiling significantly increased dry weight of aboveground
parts and roots, significantly decreased root shoot ratio, significantly
increased WUE of individual plants, and further clarified the effect of
subsoiling on plant growth and dry matter accumulation. Through analysis, it
was also find that the promotion effect of subsoiling on growth and material
accumulation will weaken with time and increase the depth of subsoiling will
prolong the
maintenance time of
subsoiling.
The results showed that subsoiling significantly
increased 100 grain weight and yield, and significantly increased the
population WUE of maize. Ishaq et al. (2003) studied that soil nutrient utilization rate was high
after subsoiling, and soil nutrient utilization rate was positively correlated
with nutrient uptake and grain yield. concluded that subsoiling can improve
nitrogen use efficiency and grain yield. Zheng et al. (2015) believed that subsoiling can increase the yield of
maize and wheat in Northeast, Northwest and North China, and the yield of plots
with continuous subsoiling and no tillage increased significantly. Through the
analysis of population WUE, yield and component factors in this experiment, the
promotion effect of subsoiling on maize yield and population WUE was clarified,
which further confirmed the previous research conclusions. Based on the analysis of the
experimental results, it is considered that increasing the subsoiling depth is
an effective method to improve its effect, which can significantly improve the
crop yield and population WUE.
Conclusion
In
conclusion, subsoiling can effectively improve the soil structure, enhance the
water holding capacity of the soil in arid areas, delay water loss, improve
root activity, net photosynthetic rate, dry matter accumulation and WUE, and
promote crop growth and yield. Subsoiling in autumn has the best effect on soil
improvement. Increasing the subsoiling depth properly can improve its effect,
but will gradually weaken with the passage of time.
Acknowledgment
Thanks
to the Project of Natural Science Foundation of Jilin Province (No. 202512JC010272903) and China National Corn
Industry Technology System Project (No. : CARS-02-42) for supporting this
research. I would like to thank corresponding author Professor Gu Yan and
Researcher Bian Shaofeng
for their guidance and help in writing this article.
Author Contributions
WY and SB conceived the idea; LZ, HZ and GT contributed in
planning the experiments; CX, NS and FL participated in the implementation of
the experiment; WY, YG and CX analyzed data; YG, SB and WY finalized the paper.
Conflict
of Interest
There is no conflict of interest among the authors
and institutions where the research has been conducted
Data
Availability Declaration
Primary and supplementary data reported in this
article are available with the corresponding authors
References
Bao SD (2000). Soil Agrochemical Analysis, 3rd
edn. China
Agriculture Press, Beijing, China
Baumhardt RL, OR Jones, RC Schwartz
(2008). Long-term effects of profile-modifying deep plowing on soil properties
and crop yield. Soil Sci Soc Amer J 72:677682
Cai HG,
W Ma, XZ Zhang, JQ Ping, XG Yan, JZ Liu, JC Yuan, LC Wang, J Ren (2014). Effect
of subsoil tillage depth on nutrient accumulation, root distribution, and grain
yield in spring maize. Crop J 5:297307
Feng Y, CL Wang, YX Zhang, JH
Zhang, EEDG Bao, LH Gao, D Wang, D Wang, W Zheng, C Zhang (2015). Effects of
deep scarification on yield and photosynthetic characteristics of maize in Dry
Irrigated Area. J Jilin
Agric Sci 1:2328
Ghosh PK, M Mohanty, KK
Bandyopadhyay, DK Painuli, AK Misra
(2005). Growth, competition, yields advantage and economics in soybean/pigeonpea intercropping system in semi-arid tropics of
India. Field Crops Res 1:9097
Guan DH, MM Al-Kaisi, YS Zhang, LS Duan, WM Tan, MC Zhang, ZH Li (2014).
Tillage practices affect biomass and grain yield through regulating root
growth, root-bleeding sap and nutrients uptake in summer maize. Field Crops Res 157:8997
Hamilton
GJ, D Bakker, G Akbar, I Hassan, Z Hussain, A McHugh, S Raine (2019). Deep
blade loosening increases root growth, organic carbon, aeration, drainage,
lateral infiltration and productivity. Geoderma 345:7292
Han XZ, WX Zou, FX Wang, FJ Wang
(2009). Construction effect of fertile cultivated layer in black soil. Chin J Appl Ecol 12:29963002
He J, HW Li, HT Chen, CY Lu, QJ
Wang (2018). Research progress of conservation tillage technology and machine. Trans Chin Soc Agric Machinery 4:119
He J, HW Li, XY Wang, AD McHugh,
WY Li, HW Gao, NJ Kuhn (2006). The adoption of annual subsoiling as
conservation tillage in dryland maize and wheat cultivation in northern China. Soil Till Res 94:493502
Holloway
RE, AR Dexter (1991). Tillage and compaction effects on soil properties, root
growth and yield of wheat during drought in a semi-arid environment. Soil Technol 3:233253
Ingrid GM, C Prat, C Ovalle, A Pozo, N Stolpe, E Zagal (2012). Subsoiling improves conservation tillage in
cereal production of severely degraded Alfisols under
Mediterranean climate. Geoderma
189190:1017
Ishaq DM, M Ibrahim, R Lal (2003).
Tillage and fertilizer effects on root growth of wheat and cotton on a sandy
clay loam in Pakistan. J Sustain Agric 3:4357
Izumi Y, T Yoshida, M Iijima (2009). Effects of subsoiling to the non-tilled
field of wheat-soybean rotation on the root system development, water uptake,
and yield. Plant Prod Sci 3:327335
Jin PY, W Ren, HB Tao, P Wang
(2014). Effects of subsoiling on dry matter production, photosynthetic
performance and root development of summer maize. J Maize Sci 1:114120
Kaur R, VK Arora (2019). Deep
tillage and residue mulch effects on productivity and water and nitrogen
economy of spring maize in north-west India. Agric Water Manage 213:724731
Li LJ, YH Cui, Q Li, QL Xue, M Zhao (2011). Effect on yield performance of early
spring maize in strip deep tillage. Crops
5:9699
Liu WL,
SX Cheng, N Li, J Wu, L Yang, CH Li, YL Zhao (2020). Effects of time and
pattern of deep tillage on topsoil nutrient content, yield of winter wheat and
summer maize in lime concretion black soil. J
Henan Agric Sci 3:816
Liu ZD, ZG Liu, DF Ning, AZ Tai,
JQ Nan, X Zhang, JF Xiao (2015). Effects of subsoiling tillage on water
utilization and yield of maize. J Irrig Drain 5:612
Lv GH, W Han, HB
Wang, WB Bai, JQ Song (2019). Effect of subsoiling on tillers, root density and
nitrogen use efficiency of winter wheat in loessal soil. Plant Soil Environ 9:456462
Ping CZ, M Hong, WD Wang, BYNML
Zhao, L Mei, PF Liu, WYG Zhao (2020). Effect of tillage management modes on
farmland physical properties in black soil region. Chin Agric Sci Bull 7:8389
Qi H, M Liu, WJ Zhang, ZP Zhang,
XF Li, ZW Song, JL Yu, YN Wu (2012). Effect of deep loosening mode on soil
physical characteristics and maize root distribution. Acta Agric Boreali-Sin 4:191196
Qin HL,
WS Gao, YC Ma, L Ma, CM Yin (2008). Effects of subsoiling on soil moisture
under no-tillage 2 years later. Sci Agric Sin 1:7885
Schneider F, A Don, I Hennings, O Schmittmann, SJ
Seidel (2017). The effect of deep tillage on crop yield What do we really
know? Soil Till Res 174:193204
Wang JD,
DJ Cui, S Li, ZH Liu, SL Zhuang, SH Song, XW Liu (2019). Effect of subsoiling
time on physical and chemical properties of lime concretion black soil under
wheat-corn continuous cropping mode. Shandong
Agric Sci 10:8690
Wang SB, LL Guo, PC Zhou, XJ
Wang, Y Shen, HF Han, TY Ning, K Han (2019). Effect of subsoiling depth on soil
physical properties and summer maize (Zea mays L.)
yield. Plant, Soil Environ 65:131137
Wang XY, HW Gao, HW Li, XX Zhou
(2000). Experimental study on runoff and erosion under conservative tillage. Trans CSAE 3:6669
Wei GJ, SC Jian, HM Fang, QJ
Peng, MM Niu (2019). Current situation and prospect
of conservation tillage technology in dry-farming areas of North China. J Chin Agric Mech 3:195200, 211
Xiao JB,
ZX Sun, JT Yang, YL Zhang, JM Zheng, L Liu (2011). Effect of subsoiling on soil
water and crop yield in semi-arid area. Chin
J Soil Sci 3:709714
Xie GH, XF Yu, JL Gao, SP Hu, HZ
Bao, FG Wang, J Liu (2019). Effects of the deep pine and controlled-release
fertilizer on the photosynthetic characteristics and yield of maize. J Northern Agric 5:5459
Xie JH, LL Wang, LL Li, JA Coulter,
Q Chai, RZ Zhang, ZZ Luo, P Carberry, KPC Rao (2020). Subsoiling increases
grain yield, water use efficiency, and economic return of maize under a fully
mulched ridge-furrow system in a semiarid environment in China. Soil Till Res 199:104584
Xu L, ZC Wang, CW Zhao, MW Zhu,
BW Wei (2012). Effect of sub-soiling on soil physical characteristics of
low-yield dryland in the West of Jilin Province. Soil Crop 2:121125
Zhai Z, YY Li, HC Pang, J Wang, L
Zhang, GH Dong, JJ Guo, ZH Guo (2016). Study on present situation and
characteristics of plow pan in the northern region of Huang Huai
Hai Plain. Sci Agric Sin 12:23222332
Zhang Q, H Wang, SL Wang, YH
Zhang, R Wang, XL Wang, J Li (2020). Effects of tillage alternation pattern
with subsoiling on soil physical and chemical properties and spring maize yield
in the Loess Plateau, China. Chin J Appl Ecol 2:459466
Zhang
RF, HS Yang, JL Gao, YQ Zhang, ZG Wang, XY Fan, WB Bi (2015). Effect of
subsoiling on root morphological and physiological characteristics of spring maize. Transactions CSAE 5:7884
Zhang
XY, D Pei, SY Chen (2004). Root growth and soil water utilization of winter wheat
in the North China Plain. Hydrol Proc 12:22752287
Zhao YL, ZW Xue,
HB Guo, XY Mu, CH Li (2014). Effects of tillage and straw returning on water
consumption characteristics and water use efficiency in the winter wheat and
summer maize rotation system. Sci Agric Sin
17:33593371
Zheng CY, ZW Yu, YL Zhang, D
Wang, Y Shi, ZZ Xu (2013). Effects of subsoiling and supplemental irrigation on
dry matter production and water use efficiency in wheat. Acta Ecol Sin 7:22602271
Zheng K, J He, HW Li, QJ Wang,
WY Li (2015). Meta-analysis on maize and wheat yield under subsoiling in
Northern China. Trans CSAE 22:715
Zhu XC, FB Song, SQ Liu, TD Liu
(2011). Effects of arbuscular mycorrhizal fungus on photosynthesis and water
status of maize under high temperature stress. Plant Soil 346:189199
Zou Q (1997). Instruction
of Plant Physiological and Biochemical Experiments. China Agriculture
Press, Beijing, China