AU2020101354A4

AU2020101354A4 - Device for applying nitrogen fertilizer

Info

Publication number: AU2020101354A4
Application number: AU2020101354A
Authority: AU
Inventors: Na Li; Jun Ma; Yongjian Sun; Zhiyuan Yang
Original assignee: Sichuan Agricultural University
Current assignee: Sichuan Agricultural University
Priority date: 2020-07-13
Filing date: 2020-07-13
Publication date: 2020-08-20
Anticipated expiration: 2028-07-13

Abstract

The present invention relates to a device for applying nitrogen fertilizer. The device is equipped with a fertilizing box which can be easily detached for adding water and fertilizer, and it is convenient for the staff to mix the fertilizing box evenly, so that the fertilizer and water inside the fertilizing box can be mixed evenly. Applying fertilizer with the device can significantly enhance the production of rice and/or the utilization efficiency of nitrogen fertilizer. 15 1 12 FIG. 3 2/2

Description

1 12

FIG. 3

2/2

DEVICE FOR APPLYING NITROGEN FERTILIZER TECHNICAL FIELD

[00011 The present invention relates to a device for applying nitrogen fertilizer, which

is used for fertilization to enhance the rice yield and/or the utilization efficiency of nitrogen

fertilizer.

BACKGROUD

[00021 At present, the average amount of nitrogen fertilizer used per season in rice

field in China is about 180 kg-hm 2 , which is about half higher than the world average. The

higher nitrogen fertilizer input in the production of Oryza sativa L. in China is closely related to

the lower technical level of nitrogen fertilizer management mastered by farmers, which is also

the objective requirement to maintain high and stable yield in the production of Oryza sativa L.

in China to meet the food security. Based on this, the research on nitrogen fertilizer management

in rice in China is mainly based on the premise of high and stable yield. Through continuous

improvement of fertilization technology, the utilization efficiency of nitrogen fertilizer is

enhanced and the input of nitrogen fertilizer is gradually reduced. Leaf age-based nitrogen

application mode of rice is fractional application of nitrogen fertilizer based on leaf age

diagnosis, which determines the leaf age of critical growth period of rice according to the

synchronous rule of the differentiation and growth of leaves and various organs, and applies

nitrogen fertilizer fractionally in different stages according to the difference of nitrogen fertilizer

demand and the leaf age. Currently, this technology has been widely used in rice production in

China. Nitrogen fertilizer application technology widely used in rice production in developed

countries is the real-time nitrogen management mode proposed by International Rice Research

Institute. In this mode, base fertilizers are usually not applied in rice production. Whether the

growing rice needs topdressing is determined only by comparing the SPAD value of leaves and

the set threshold value. If the SPAD value of newly developed leaves of the plant is lower than

the threshold, nitrogen fertilizer will be applied; otherwise, no nitrogen fertilizer will be applied.

In addition to the above two application technologies of nitrogen fertilizer in rice, the most

widely used nitrogen fertilizer application technology in rice production in China is one-off

application of base fertilizer, that is, nitrogen fertilizer needed for the whole growth period of rice is applied in one time as base fertilizer before transplanting.

[0003] The above three application technologies of nitrogen fertilizer are the most

representative management measures of nitrogen fertilizer in rice production in China. For rice

leaf age-based nitrogen application mode, nitrogen fertilizer is usually divided into base fertilizer,

tillering fetilizer and panicle fertilizer for application, with high rice yield and high utilization

efficiency of nitrogen fertilizer; for real-time nitrogen management mode, the application

frequency of nitrogen fertilizer is not fixed, usually 4-7 times, with high rice yield and high

utilization efficiency of nitrogen fertilizer; for one-off application of base fertilizer, nitrogen

fertilizer is applied only once, the rice yield and the utilization efficiency of nitrogen fertilizer

are both low. In the above three application technologies of nitrogen fertilizer, although the

application frequency of nitrogen fertilizer in the one-off application of base fertilizer is low, but

the rice yield and the utilization efficiency of nitrogen fertilizer are poor, thus not meeting the

requirements of high and stable production of rice in China; although the utilization efficiency of

nitrogen fertilizer is high in the real-time nitrogen fertilizer management, the detection of leave

SPAD is complex and the apparatus is expensive; although high yield of rice is achieved in the

rice leaf age-based nitrogen application mode, there is a gap in the utilization efficiency of

nitrogen fertilizer compared with that of the real-time nitrogen management mode.

[0004] In addition, the tools used in fertilization can also directly affect the quality of

fertilization.

SUMMARY

[0005] To solve the problems in the prior art, the present invention provides a device

for applying nitrogen fertilizer to rice, which has advantages of widely applicable, simple and

easy to operate.

[0006] An objective of the invention is to provide a device for applying nitrogen

fertilizer.

[0007] A device for applying nitrogen fertilizer, comprising a bottom board, wherein

the top end of the bottom board isfixedly connected with a bedplate, a power switch is clamped

on the surface of the bedplate, a push rod is welded to the top end of the bedplate, a driving

motor is fixedly connected in the middle of the bottom end of the bedplate by screws, and both

ends of the driving motor are connected with driving wheels in a transmission way; a fertilizing box is fixedly connected in the middle of the top end of the bottom board, a hydraulic pump is disposed at one end of the fertilizing box through a connecting pipeline, the hydraulic pump is fixedly connected to the bottom board by screws, the top end of the hydraulic pump is fixedly connected with a metal hose through a water pipe, the metal hose is connected with a spray head, water injection nozzles are opened on the surface of the spray head, spacing boards are connected to both sides of the spray head, adjusting plates are connected between the spacing boards in a sliding mode, the inner side of the spacing board at one side is provided with a liquid reservoir, a return-flow catheter is connected to the middle of the bottom end at one side of the spray head, and both ends of the bottom board are connected with guiding wheels.

[0008] The device of the present invention can be used for fertilization.

[0009] The specific method of applying nitrogen fertilizer with the device of the

invention includes the following steps:

(1) transplanting rice;

(2) applying nitrogen fertilizer to the rice on days 7, 14, 35, 49, 56, 70 and 77 after the rice

transplanting; the application rate of nitrogen fertilizer on day 7 is 12-18 kg-hm-2 ; the application rate of nitrogen fertilizer on day 14 is 12-18 kg-hm-2 ; the application rate of nitrogen fertilizer on

day 35 is 24-36 kg-hm-2 ; the application rate of nitrogen fertilizer on day 49 is 12-18 kg-hm-2;

the application rate of nitrogen fertilizer on day 56 is 12-18 kg-hm-2 ; the application rate of

nitrogen fertilizer on day 70 is 12-18 kg-hm-2 ; and the application rate of nitrogen fertilizer on

day 77 is 12-18 kg -hm2

[00010] The application rates of nitrogen fertilizer in the invention are all calculated on

the basis of pure nitrogen; the application rates of phosphorous fertilizer in the invention are all

calculated on the basis of P 2 0 5 ; and the application rates of potash fertilizer in the invention are

all calculated on the basis of K20.

[00011] Wherein, phosphorous fertilizer and potash fertilizer are applied in onetime as

base fertilizer before the rice transplanting; the application rate of the phosphorous fertilizer is

50% of the total weight of nitrogen fertilizer applied on days 7, 14, 35, 49, 56, 70 and 77 after

the rice transplanting, and the application rate of the potash fertilizer is the same as the total weight of nitrogen fertilizer applied on days 7, 14, 35, 49, 56, 70 and 77 after the rice transplanting.

[00012] Wherein, the rice is transplanted in the field with lower fertility (with a soil

organic matter content not higher than 1%), and the application rates of nitrogen fertilizer on

days 7, 14, 35, 49, 56, 70 and 77 after the rice transplanting are 18 kg-hm-2 , 18 kg-hm 2 , 36

kg-hm-2 , 18 kg-hm 2 , 18 kg-hm 2 , 18 kg-hm 2 and 18 kg-hm 2 , respectively.

[00013] Wherein, the rice is transplanted in the field with medium fertility (with a soil

organic matter content in the range of 1%- 3 %), and the application rates of nitrogen fertilizer on

days 7, 14, 35, 49, 56, 70 and 77 after the rice transplanting are 15 kg-hm-2 , 15 kg-hm 2 , 30

S kg-hm 2 , 15 kg-hm 2 , 15 kg-hm 2 , 15 kg-hm 2 and 15 kg-hm 2 , respectively.

[00014] Wherein, the rice is transplanted in the field with higher fertility (with a soil

organic matter content higher than 3%), and the application rates of nitrogen fertilizer on days 7,

14, 35, 49, 56, 70 and 77 after the rice transplanting are 12 kg-hm-2 , 12 kg-hm 2 , 24 kg-hm 2 , 12

kg-hm-2 , 12 kg-hm 2 , 12 kg-hm 2 and 12 kg-hm 2 , respectively.

[00015] Wherein, the rice transplanting includes artificial transplanting and

rice-seedling transplanting with machine, and the artificial transplanting includes equal

row-spacing cultivation, wide-narrow row cultivation and triangle cultivation.

[00016] Furthermore, the row spacing in the equal row-spacing cultivation is 25-35 cm,

and the plant spacing in the equal row-spacing cultivation is 15-20 cm; the wide row spacing in

the wide-narrow row cultivation is 35-45 cm, the narrow row spacing in the wide-narrow row

cultivation is 25-33 cm, and the plant spacing in the wide-narrow row cultivation is 15-20 cm;

the plant spacing and the row spacing in the triangle cultivation are both 30-40 cm; the row

spacing in the rice-seedling transplanting with machine is 20-30 cm, and the plant spacing in the

rice-seedling transplanting with machine is 15-20 cm.

[00017] Wherein, field management of rice plants is conducted together with the

application of nitrogen fertilizer after the rice transplanting.

[00018] Furthermore, operating procedures for the conventional irrigation are: during

the period from rice transplanting to the critical leaf-age stage of effective tillering, a water layer with a depth of 1-3 cm is maintained in the field; during the period from the critical leaf-age stage of effective tillering to the jointing stage, the field is sunned (until the crack width in the field reaches 1.5-2.0 cm); after the jointing stage, a water layer with a depth of 1-3 cm is maintained in the field, until drying up naturally 1 week before the harvest.

[00019] Furthermore, operating procedures for the alternative irrigation are: firstly transplanting in shallow water with a depth of 0.8-1.2 cm; upon the transplanting, a water layer

with a depth of 1.8-2.2 cm is maintained in the field until seedling reviving; during the period

from reviving to booting, no water layer is maintained in the field, with the soil moisture content

at 70%- 8 0% of the saturated moisture content; during the effective tillering stage, the tiller

number in the field reaches the planned panicle number and the field is sunned; entering the

booting stage, a water layer with a depth of 1-3 cm is maintained in thefield; during the period

from heading to maturity, an alternative irrigation mode of saturated water irrigation, naturally

drying up to a soil water potential of -20 kPa to -25 kPa, then saturated water irrigation

repeatedly, is adopted.

[00020] The water management in the field management can include the following two ways: (i) conventional submerged irrigation, in which a water layer with a depth of 1-3 cm is

maintained in the field after the rice transplanting, the field is sunned during the period from the

critical leaf-age stage of effective tillering to the jointing stage (the crack width in the field

reaches 1.5-2.0 cm), then a water layer with a depth of 1-3 cm is maintained all times until

drying up naturally 1 week before the harvest; (ii) controlled alternative irrigation, in which

seedlings are transplanted in shallow water (about 1 cm), a water layer with a depth about 2 cm

(1.8-2.2 cm) is maintained for 5-7 days after the transplanting to ensure seedling reviving, no

water layer is maintained during the period from reviving to booting, with the soil moisture

content at about 70%- 8 0% of the saturated moisture content; during the effective tillering stage,

the tiller number in the field reaches the planned panicle number and the field is sunned; a water layer with a depth of 1-3 cm is maintained at the soil surface during the booting stage; during the

period from heading to maturity, an alternative irrigation mode of saturated water irrigation,

naturally drying up to a soil water potential of -20 kPa to -25 kPa (determined with a vacuum

gauge soil negative pressure meter manufactured by Nanjing Soil Research Institute, Chinese

Academy of Sciences), then saturated water irrigation repeatedly, is adopted.

[00021] Other aspects of field management, including weeding and pest control, are the

same as in conventional rice production.

[00022] Fertilization with the device of the invention can significantly enhance the rice

yield and/or the utilization efficiency of nitrogen fertilizer.

[00023] The device of the invention is suitable for ecological areas where

middle-season rice is planted and the rice field where irrigation and drainage are convenient.

[000241 Beneficial effects of the invention are as follows:

[00025] In the device of the invention, a spray head, a metal hose, a water pipe and a

hydraulic pump are arranged to facilitate sucking liquid fertilizer from the interior of the

fertilizing box through a hydraulic pump and delivering it to the metal hose through the water

pipe, and then delivering the liquid fertilizer to the spray head under the pressure to achieve the

effect of spraying; the spraying position can be adjusted from multiple angles through the metal

hose.

[00026] In the device of the invention, spacing boards, adjusting plates, a return-flow

catheter and a liquid reservoir are arranged so that when the spray head is required to spray

different range of locations, the adjusting plates can move in the groove of the spacing boards

by manually sliding the adjusting plates, so as to enclose the water injection nozzles on the

surface of the spray head by the adjusting plates according to the spraying range to achieve the

enclosing effect. Therefore, the liquid fertilizer not sprayed out and partially enclosed in the

water injection nozzles can flow back to the interior of the return-flow catheter through the

liquid reservoir in the interior of the spacing board, achieving the backflow effect and

facilitating the cyclic utilization.

[00027] In the device of the invention, a fertilizing box is arranged so that it can be

detached for adding water and fertilizer, and it is convenient for the staff to mix the fertilizing

box evenly, thereby mixing the fertilizer and water inside the fertilizing box evenly.

[000281 The device for applying nitrogen fertilizer of the invention is widely applicable,

which is used for applying nitrogen fertilizer regularly and quantitatively according to different

growth stages of rice, and the operation is simple and easy. Compared to real-time nitrogen management mode and leaf age-based nitrogen application mode, the method of applying nitrogen fertilizer with the device of the invention can significantly enhance the rice yield and the utilization efficiency of nitrogen fertilizer concurrently in the field with lower fertility; has a higher utilization efficiency of nitrogen fertilizer than the leaf age-based nitrogen application mode in the field with medium fertility; and has a higher yield in thefield with higher fertility than that of real-time nitrogen management mode.

BRIEF DESCRIPTION OF THE DRAWINGS

[00029] FIG. 1 is an overall structural diagram of the invention.

[00030] FIG. 2 is a structural diagram of the surface of the spray head of the invention.

[00031] FIG. 3 is a local structural diagram of the spray head of the invention.

DESCRIPTION OF THE EMBODIMENTS

[000321 In order to make the objective, technical scheme and advantages of the present

invention more clear, the technical scheme of the present invention will be described in detail

below. Obviously, the described embodiments are only part of the embodiments of the

invention. Based on the embodiments of the invention, all other implementations obtained by

persons with ordinary skills in the art without creative labors are in the protection scope of the

invention.

[00033] As shown in FIGs. 1-3, a device for applying nitrogen fertilizer, comprising a

bottom board 10, wherein the top end of the bottom board is fixedly connected with a bedplate

7 at one side, a power switch 6 is clamped on one side of the surface of the bedplate 7, a push

rod 5 is welded to one side of the top end of the bedplate 7, a driving motor 8 is fixedly

connected in the middle of the bottom end of the bedplate 7 by screws, and both ends of the

driving motor 8 are connected with driving wheels 9 in a transmission way; a fertilizing box 4

is fixedly connected in the middle of the top end of the bottom board 10, a hydraulic pump 17

is disposed at one end of the fertilizing box 4 through a connecting pipeline, the hydraulic

pump 17 is fixedly connected to the bottom board 10 by screws, one side of the top end of the

hydraulic pump 17 is fixedly connected with a metal hose 2 through a water pipe 3, one end of

the metal hose 2 is fixedly connected with a spray head 1, water injection nozzles 14 are opened on the surface of the spray head 1, spacing boards 15 are fixedly connected to both sides of the spray head 1, adjusting plates 13 are connected between the spacing boards 15 in a sliding mode, the inner side of the spacing board 15 at one side is provided with a liquid reservoir 16, a return-flow catheter 12 is connected to the middle of the bottom end at one side of the spray head 1, and both ends of the bottom board 10 are fixedly connected with guiding wheels 11.

[00034] Wherein, the interior of the metal hose 2 is sleeved with a rubber tube, and a

sealing cartridge is further fixedly connected at the connection of the metal hose 2 and the

spray head 1. The metal hose 2 is made of stainless steel.

[00035] Wherein, two adjusting plates 13 are arranged totally, the adjusting plates 13

are made of plastics. The adjusting plates 13 have detachable structures, it is facilitate for

blocking up the water injection nozzles 14 on the surface of the spray head 1 with the adjusting

plates 13 to adjust the spraying range of the spray head1 conveniently.

[00036] Wherein, the return-flow catheter 12 is a rubber hose. The retum-flow catheter

12 runs through the hydraulic pump 17, and the length of the return-flow catheter 12 is greater

than the straight-line distance between the spray head 1 and the hydraulic pump 17. The

retum-flow catheter 12 is arranged under the middle of the liquid reservoir 16 so as to recycle

the fertilizer efficiently.

[00037] Wherein, an influent hopper is further clamped at the top end of the fertilizing

box 4, a level gauge is also embedded at one side of the surface of the fertilizing box 4, and the

fertilizing box 4 has a round barrel structure which is detachable.

[00038] Wherein, the liquid reservoir 16 is rectangular in shape. The connection of the

liquid reservoir 16 and the retum-flow catheter 12 is provided with screw threads. The two ends

of the liquid reservoir 16 and the spacing board 15 are in a closed structure.

[00039] Wherein, water injection nozzles 14 are arranged on the surface of the spray

head 1 in a rectangular array. The water injection nozzles 14 are elliptical in shape.

[00040] It should be noted that, the present invention relates to a device for applying

nitrogen fertilizer. During use, the fertilizing box 4 is firstly detached, into which is then added fertilizer and water and mixed evenly. The fertilizing box 4 is reinstalled, the power switch 6 at one side of the surface of the bedplate 7 is then pressed to enable the driving motor 8 and the hydraulic pump 17 to run, and the driving wheels 9 start rotating under the action of the driving motor 8. The guiding wheels 11 are convenient for adjusting positions. The push rod 5 is pushed manually to move the bottom board 10 forwardly. During the movement of the bottom board 10, the liquid fertilizer in the fertilizing box 4 is delivered into the water pipe 3 through the hydraulic pump 17, and the liquid fertilizer enters the metal hose 2 through the water pipe 3 under pressure, and then enters the spray head 1, thereby being sprayed out from the water injection nozzles 14 on the surface of the spray head 1. The position of the metal hose 2 can be changed manually so that the spray head 1 can spray to different locations, thus achieving the adjustment of positions. When the spraying range needs to be adjusted, the adjusting plates 13 can slip in the groove of the spacing board 15 by manually moving the adjusting plates 13, so as to enclose partial water injection nozzles 14 on the surface of the spray head 1 by the adjusting plates 13, and thus control the spraying range of the spray head 1. Therefore, the liquid fertilizer not sprayed out can flow back into the return-flow catheter 12 through the liquid reservoir 16 at one side, and then flow into the hydraulic pump 17 through the return-flow catheter 12 to achieve the backflow effect and facilitate spraying again. The liquid fertilizer capacity inside the fertilizing box 4 can be observed by the level gauge on the surface of the fertilizing box 4.

[00041] The following provides the methods and data of fertilization with the device for

applying nitrogen fertilizer of the invention.

Embodiment 1

[00042] The fields with medium fertility were selected for field tests, in which nitrogen

fertilizer is applied with the device for applying nitrogen fertilizer of the invention regularly and

quantitatively.

(1) Test location and method

[00043] The tests were conducted in 2014 at the test site of Rice Research Institute of

Sichuan Agricultural University, Wenjiang District, Chengdu, Sichuan, for which Yixiang 3724

was selected as the test material. The topsoil of the test field is sandy loam with medium fertility, of which the organic matter content is 14.19 g kg , the content of total nitrogen is 0.118%, the content of available nitrogen is 97.6 mg kg-1, the content of available phosphorus is 19.8 mg kg-1, and the content of available potassium is 82.4 mg kg-1. Seeding was conducted on March 27th, and seedlings were raised under drought conditions. Transplanting was conducted in a single seedling manner on April 30th, at which the leaf age was four leaves and one shoot, the row spacing and plant spacing were 33.3 cm x 16.7 cm. Rice was harvested on September 1st. Single factor randomized block design was applied in the tests. Different application methods of nitrogen fertilizer were treatment factors, including one-off application of base fertilizer, rice leaf age-based nitrogen fertilizer application mode, real-time nitrogen management mode and regular and quantitative nitrogen fertilizer application mode, with the specific application methods of nitrogen fertilizer seen in Table 1. Additionally, no nitrogen fertilizer application was used as the control. Conventional submerged irrigation was used for water management, i.e., after the rice transplanting, a water layer of 1-3 cm was maintained at the field surface all times; during the effective tillering stage, the tiller number in the field reaches the planned panicle number and the field is sunned; after then a water layer of 1-3 cm was maintained all times until drying up naturally 1 week before the harvest. Other field management measures were the same as in conventional rice production.

Table 1 Different application methods of nitrogen fertilizer

Application Application rate and time of Nitrogen fertilizer

method of Base fertilizer Tillering Spikelet-promoting Flower-protecting

nitrogen (kg-hm-2) fertilizer fertilizer fertilizer

fertilizer (kg-hm- 2) (kg-hm-2 ) (kg-hm-2)

From 7 days after transplanting to full heading stage, if

SPAD readings of Chlorophyll meter < 37.5, application Real-time of nitrogen fertilizer at 15 kg-hm-2 ; if SPAD > 37.5, no nitrogen 0 nitrogen fertilizer application. Wherein, at the jointing management stage (inverse 4th leaf stage), if SPAD < 37.5, application mode of nitrogen fertilizer at 30 kg-hm-2, determine once a

week.

Rice leaf

age-based

nitrogen 45(30%) 45(30%) 30(20%) 30(20%) fertilizer

application

mode

One-off

application of 105 (70%) 45(30%) 0 0

base fertilizer

Regular and On days 7, 14, 35, 49, 56, 70 and 77 after transplanting, application of

quantitative nitrogen fertilizer at 15, 15, 30, 15, 15, 15 and 15 kg-hm-2 on basis of pure

nitrogen nitrogen, respectively.

fertilizer

application

mode

(2) Testing items

0 Determination of nitrogen accumulation

[00044] In the mature stage, 5 representative plants were selected according to the

average number of tillers per treatment. The over-ground parts were dried and then weighed,

crushed and sieved. A Kjeldahl apparatus (FOSS-8400) was used to determine the nitrogen

content of plants, which was multiplied by the dry matter weight to gain the nitrogen

accumulation in the mature stage. The recovery of nitrogen fertilizer was obtained through

dividing the difference of nitrogen accumulation in the mature stage between nitrogen

application and the blank control by the application rate of nitrogen fertilizer. The agronomic

utilization efficiency of nitrogen fertilizer was obtained through dividing the yield difference

between nitrogen application and the blank control by the application rate of nitrogen fertilizer.

@ Inspection on yield

[00045] In the mature stage, rice in each district was reaped and threshed separately,

then dried and weighed. The weight was converted to standard weight according to a water content of 13.5%, which was then divided by the hole number of rice actually harvested and multiplied by the hole number of rice per unit area to get the yield.

(3) Test results

[00046] Determination was conducted with the above method, with the results shown in

Table 2.

Table 2 Rice yield and utilization efficiency of nitrogen fertilizer under different application

methods of nitrogen fertilizer

Agronomic Application Application rate Recovery of utilization method of of nitrogen Yield nitrogen efficiency of nitrogen fertilizer (kilogram/hectare) fertilizer nitrogen fertilizer fertilizer (kilogram/hectare) (%) (kilogram/kilogram) Regular and

quantitative

nitrogen 120 10312a 65.21a 27.08a fertilizer

application

mode

Real-time

nitrogen 120 9787b 62.38b 22.71b management

mode

Rice leaf

age-based

nitrogen 150 10432a 57.41c 22.47b fertilizer

application

mode

One-off 150 9321c 42.15d 15.06c application of base fertilizer

Blank control 0 7062d -

[00047] In Table 2, a, b, c after the data indicate that the difference reaches a level of

5%.

[00048] As can be seen from Table 2, the yield in the regular and quantitative nitrogen

fertilizer application mode was enhanced by 10.63% and 5.36% respectively compared to that in

one-off application of base fertilizer and real-time nitrogen management mode, meanwhile, the

recovery of nitrogen fertilizer and the agronomic utilization efficiency of nitrogen fertilizer for

characterizing the utilization efficiency of nitrogen fertilizer were enhanced by 54.71%, 4.54%,

7.98% and 19.24%, respectively; compared to the rice leaf age-based nitrogen fertilizer

application mode, the yield difference in the regular and quantitative nitrogen fertilizer

application mode was not significant, while the recovery of nitrogen fertilizer and the agronomic

utilization efficiency of nitrogen fertilizer were enhanced by 13.59% and 20.52%, respectively.

The results showed that the regular and quantitative method of applying nitrogen fertilizer can

significantly enhance the rice yield and/or the utilization efficiency of nitrogen fertilizer.

Embodiment 2

[00049] The fields with high fertility were selected for field tests, in which nitrogen

quantitatively.

(1) Test location and method

[00050] The tests were conducted in 2014 at the test site of Rice Research Institute of

was selected as the test material. The topsoil of the test field is sandy loam with high fertility, of

which the organic matter content is 22.56 g kg-, the content of total nitrogen is 0.174%, the

content of available nitrogen is 131.6 mg kg-1, the content of available phosphorus is 30.8 mg

kg-1, and the content of available potassium is 107.4 mg kg-1. Seeding was conducted on March

27th, and seedlings were raised under drought conditions. Transplanting was conducted in a

single seedling manner on April 30th, at which the leaf age was four leaves and one shoot, the

row spacing and plant spacing were 33.3 cm x 16.7 cm. Rice was harvested on September 1st.

Single factor randomized block design was applied in the tests. Different application methods of

nitrogen fertilizer were treatment factors, including one-off application of base fertilizer, rice leaf

age-based nitrogen fertilizer application mode, real-time nitrogen management mode and regular

and quantitative nitrogen fertilizer application mode, with the specific application methods of

nitrogen fertilizer seen in Table 3. Additionally, no nitrogen fertilizer application was used as the

control. Alternative irrigation was used for water management, i.e., seedlings were transplanted

in shallow water (about 1 cm); a water layer with a depth about 2 cm was maintained for 5-7

days after the transplanting to ensure seedling reviving, no water layer is maintained during the

period from reviving to booting, with the soil moisture content at about 70%- 8 0% of the

saturated moisture content; during the effective tillering stage, the tiller number in the field

reached the planned panicle number and the field was sunned; a water layer with a depth of 1-3

cm was maintained at the soil surface during the booting stage; during the period from heading

to maturity, an alternative irrigation mode of saturated water irrigation, naturally drying up to a

soil water potential of -20 kPa to -25 kPa (determined with a vacuum gauge soil negative

pressure meter manufactured by Nanjing Soil Research Institute, Chinese Academy of Sciences),

then saturated water irrigation repeatedly, was adopted. Other field management measures were

the same as in conventional rice production.

Table 3 Different application methods of nitrogen fertilizer

Application Application rate and time of Nitrogen fertilizer

method of Base fertilizer Tillering Spikelet-promoting Flower-protecting

nitrogen (kg-hm-2) fertilizer fertilizer fertilizer

fertilizer (kg-hm- 2) (kg-hm-2 ) (kg-hm-2)

From 7 days after transplanting to full heading stage, if

week.

Rice leaf

age-based

nitrogen 45(30%) 45(30%) 30(20%) 30(20%) fertilizer

application

mode

One-off

application of 105 (70%) 45(30%) 0 0

base fertilizer

quantitative nitrogen fertilizer at 12, 12, 24, 12, 12, 12 and 12 kg-hm-2 on basis of pure

nitrogen nitrogen, respectively.

fertilizer

application

mode

(2) Testing items

0 Determination of nitrogen accumulation

[00051] In the mature stage, 5 representative plants were selected according to the

@ Inspection on yield

[00052] In the mature stage, rice in each district was reaped and threshed separately,

(3) Test results

[00053] Determination was conducted with the above method, with the results shown in

Table 4.

Table 4 Rice yield and utilization efficiency of nitrogen fertilizer under different application

methods of nitrogen fertilizer

quantitative

nitrogen 96 11874a 61.35a 35.54a fertilizer

application

mode

Real-time

nitrogen 105 11210b 59.71a 26.17b management

mode

Rice leaf

age-based

nitrogen 135 11946a 51.08b 25.81b fertilizer

application

mode 135 9934b 39.42c 10.90c One-off application of base fertilizer 0 8462c Blank control

[00054] In Table 4, a, b, c after the data indicate that the difference reaches a level of

5%.

[00055] As can be seen from Table 4, the yield in the regular and quantitative nitrogen

fertilizer application mode was enhanced by 19.53% and 5.92% respectively compared to that in

characterizing the utilization efficiency of nitrogen fertilizer were enhanced by 55.63%, 2.75%,

226.06% and 35.80%, respectively; compared to the rice leaf age-based nitrogen fertilizer

utilization efficiency of nitrogen fertilizer were enhanced by 20.11% and 37.70%, respectively.

[00056] In summary, applying nitrogen fertilizer with the device for applying nitrogen

fertilizer of the invention regularly and quantitatively can significantly enhance the rice yield

and/or the utilization efficiency of nitrogen fertilizer.

[00057] The aforementioned embodiments are only specific implementations of the

invention, but the protection scope of the invention is not limited thereto. Any changes or

replacements that can easily be thought of by technical personnel with ordinary skills in the art

within the technical scope disclosed in the invention shall be covered in the protection scope of

the invention. Therefore, the protection scope of the invention should be subject to the protection

scope of the claim.

Claims

Claims WHAT IS CLAIMED IS:

1. A device for applying nitrogen fertilizer, comprising a bottom board, wherein the top end

of the bottom board is fixedly connected with a bedplate, a power switch is clamped on the

surface of the bedplate, a push rod is welded to the top end of the bedplate, a driving motor is

fixedly connected in the middle of the bottom end of the bedplate by screws, and both ends of

the driving motor are connected with driving wheels in a transmission way; a fertilizing box is

fixedly connected in the middle of the top end of the bottom board, a hydraulic pump is disposed

at one end of the fertilizing box through a connecting pipeline, the hydraulic pump is fixedly

connected to the bottom board by screws, the top end of the hydraulic pump is fixedly connected

with a metal hose through a water pipe, the metal hose is connected with a spray head, water

injection nozzles are opened on the surface of the spray head, spacing boards are connected to

both sides of the spray head, adjusting plates are connected between the spacing boards in a

sliding mode, the inner side of the spacing board at one side is provided with a liquid reservoir, a

retum-flow catheter is connected to the middle of the bottom end at one side of the spray head,

and both ends of the bottom board are connected with guiding wheels.

2. The device according to claim 1, wherein the interior of the metal hose is sleeved with a

rubber tube, and a sealing cartridge is provided at the connection of the metal hose and the spray

head.

3. The device according to claim 1, wherein two adjusting plates are arranged totally, and

the adjusting plates have detachable structures.

4. The device according to claim 1, wherein the retum-flow catheter is a rubber hose, the

retum-flow catheter runs through the hydraulic pump, and the length of the retum-flow catheter

is greater than the straight-line distance between the spray head and the hydraulic pump.

5. The device according to claim 1, wherein an influent hopper is clamped at the top end of

the fertilizing box, a level gauge is embedded on the surface of the fertilizing box, the fertilizing

box has a round barrel structure which is detachable.

/ 2

FIG. 2 FIG. 1 FIGURES

/ 2

FIG. 3