A method for testing water consumption of rice

Abstract

The application discloses a kind of determination methods of testing water consumption of rice, it is related to agricultural water-saving technology field, comprising the following steps: before different drought degree test at each growth period, rice is transplanted to test pot, after reaching drought degree at each growth period, when there is water layer in test pot, the water level of test pot is measured using measuring instrument before and after two days, and daily water consumption is calculated using water balance formula, when there is no water layer in test pot, rice and wet soil weight are weighed using electronic platform scale at fixed time every day, soil moisture content at fixed time is calculated, and water is added to the level of soil moisture content of previous day using measuring cylinder, after each growth period ends, the fresh weight of randomly cut plant is weighed using electronic scale, the fresh weight change coefficient of rice at different stages is calculated, and the field water consumption of rice is obtained using the difference between initial and final soil mass, water supplement, fresh weight change coefficient and test pot surface area.The application is simple in operation, low in measurement cost, high in measurement accuracy, and can be widely applied in a wide range of occasions.

Description

Technical Field

[0001] This invention relates to the field of agricultural water-saving technology, and in particular to a method for determining the water consumption of experimental rice. Background Technology

[0002] Research on water consumption at different growth stages of rice has always been a hot topic in the field of rice water-saving technology. The feedback information provided by rice water consumption is usually used to guide irrigation or for other research. Therefore, obtaining the water consumption of rice and quantitatively expressing its characteristics is of great significance for precision irrigation and sustainable development of rice farmland.

[0003] Currently, crop evapotranspiration is mainly obtained through two methods: model simulation and measurement. Many scholars at home and abroad have proposed various models for estimating crop evapotranspiration, such as the PM model and Prierstley-Taylor model for calculating evapotranspiration on daily time scales or even smaller scales, the Thornthwaite model for calculating monthly evapotranspiration, and the Penman-Monteith (PM) single-source model and the Shuttleworth-Wallace (SW) dual-source model for calculating actual evapotranspiration under dense canopy conditions. These models are relatively complex, require many parameters, and are not easy to obtain, which limits their application. The methods for measuring crop evapotranspiration can be roughly summarized as hydrological methods, micrometeorological methods, plant physiological methods, and remote sensing methods.

[0004] However, most current weighing-based measurement methods do not take into account the accumulation of dry matter at each growth stage of the crop, as well as the changes in fresh weight of the crop during the reproductive growth stage. This can easily lead to large errors in the water consumption at each stage after measurement, and they cannot be used for overall research on large-scale crops. Summary of the Invention

[0005] This invention provides a method for determining the water consumption of experimental rice, which can solve the problem of large errors in the measurement of water consumption during the growth period in the prior art.

[0006] This invention provides a method for determining the water consumption of experimental rice, comprising the following steps: To determine whether rice experimental pots have a water layer; When there is no water layer in the rice experimental pots: Obtain the initial soil moisture content at the beginning of the rice growth stage; irrigate the rice at different growth stages to keep the soil moisture content at fixed times every day consistent with the initial soil moisture content, and record the irrigation amount at fixed times every day to calculate the irrigation amount at different growth stages. At the end of the rice growth stage, the above-ground parts of the rice plant are harvested and weighed, and the underground parts are also weighed. The fresh weight variation coefficient of rice at different growth stages is calculated using an improved formula. The improved formula for the fresh weight variation coefficient of rice is as follows: in: λ f The coefficient representing the change in fresh weight of rice during its growth stage; n represents the number of potted rice plants. m ag The above-ground fresh weight of rice in the representative treatment group; m s Represents the fresh weight of rice seedlings; This represents the ratio of fresh weight of rice in the upper and lower parts of the control group. , This represents the fresh weight of the underground portion in the control group. Represents the fresh weight of the above-ground portion; Based on irrigation volume and rice fresh weight variation coefficient at different growth stages, the water consumption of rice at different growth stages is calculated using an improved rice water consumption formula; the improved rice water consumption formula is as follows: in: ET i Represents the field water consumption during the i-th growth stage; m 0 This represents the initial weight of the potting soil; m t t represents the soil weight of the potted plant at the end of the growth stage; t represents the number of days of water stress during the growth stage. m i This represents the amount of water injected during the i-th reproductive stage; T i Represents the number of days in the i-th reproductive period; ρ w Represents the density of water; S p This represents the area of ​​the potted plant.

[0007] Preferably, it further includes: When there is a water layer in the rice experimental pot: Obtain the water level in the test basin at the same time point on the previous and following days; Based on the water levels of the previous and following days, the water consumption of rice on the following day is obtained through the water balance formula, and the water consumption of rice at different growth stages is calculated. The water balance calculation formula is as follows: in: h 1This represents the water level in the potted plant from the previous day; h 2 This represents the water level in the potted plant the following day. P Represents rainfall during a specific period; when there is no rainfall... P =0; C Represents drainage volume; when there is no drainage C =0; m i Represents the amount of water poured in; E This represents the amount of water consumed by the rice planted the following day.

[0008] Preferably, the process of determining whether the rice experimental pot has a water layer includes the following steps: Select multiple rice plants of the same variety and place them in an experimental pot; During the growth period experiment, observe whether there is a water layer in the rice experimental pots.

[0009] Preferably, the above-ground and underground parts of the rice are weighed using an electronic scale with an accuracy of 0.0001g, and the weight of the potted plant and the soil inside the pot are weighed using an electronic scale with an accuracy of 0.1g.

[0010] Preferably, the amount of water used for irrigation at different growth stages is measured using a measuring cup, and the amount of water is converted into mass after taking a fixed value based on the density of water.

[0011] This invention provides a method for determining the water consumption of experimental rice, which has the following advantages compared with the prior art: This method takes into account the transpiration of rice plants, inter-plant evaporation, and the water requirements of the plant itself, and focuses on the increment of rice fresh weight change. The improved calculation method can be more accurate and can directly calculate the overall water consumption of rice at each stage using conditions such as the number of days, the rice fresh weight change coefficient, carrier weight, and irrigation volume, thereby improving accuracy and reducing workload, and providing sufficient theoretical basis for large-scale rice planting and overall research. Attached Figure Description

[0012] Figure 1 A schematic diagram illustrating the principle steps of a method for determining the water consumption of experimental rice, provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure before the evapotranspiration experiment at each growth stage of a method for determining the water consumption of experimental rice, provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure for measuring water level before evapotranspiration experiments at each growth stage, as provided in an embodiment of the present invention for a method for determining the water consumption of experimental rice. Figure 4 is a flowchart of the operation process of the evapotranspiration test of the experimental rice water consumption method provided in the embodiment of the present invention, wherein: 4(a) is the flowchart of the operation process on the first day of the evapotranspiration test of each growth period; 4(b) is the flowchart of the operation process on the second day of the evapotranspiration test of each growth period. Figure 5 is a flowchart of the operation process after evapotranspiration test at each growth stage of a method for determining the water consumption of experimental rice provided in an embodiment of the present invention, wherein: 5(a) is a schematic diagram after evapotranspiration test at each growth stage; 5(b) is a schematic diagram of harvesting the part of rice above the soil surface for weighing; Figure 6 A schematic diagram of the structure of an experimental pot for a method of determining the water consumption of rice according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the mudguard structure of a method for determining the water consumption of experimental rice, provided in an embodiment of the present invention.

[0013] Among them: 1. Mudguard, 2. Experimental pot, 3. Experimental rice, 31. The part of the experimental rice above the soil surface, 32. The part of the experimental rice below the soil surface, 4. Electronic platform scale (50kg / 0.1g), 5. Measuring cup, 6. Electronic scale (accuracy 0.001g), 7. Ruler. Detailed Implementation

[0014] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0015] See Figure 1 As shown in the figure, this invention provides a method for determining the water consumption of experimental rice, including the following steps: Before conducting water consumption experiments at different growth stages (tillering stage, jointing and booting stage, heading and flowering stage, and milk stage) with different drought conditions (soil moisture content of 70% for mild drought, 60% for moderate drought, 50% for severe drought, and 40% for extreme drought), rice seedlings were transplanted into soil with saturated moisture content. The seedlings were then transplanted as a whole into sealed experimental pots, which were then placed in the experimental field.

[0016] When conducting experiments on water consumption under different drought conditions at various growth stages, after reaching the drought level, when there is a water layer on the field surface, the water level of the experimental basins was measured with a steel ruler for two days before and after, and the daily water consumption was calculated using the water balance formula; when there is no water layer on the field surface, the weight of rice and moistened soil was weighed with an electronic platform scale 4 at a fixed time every day, the soil moisture content at the fixed time was calculated, and water was added with a measuring cup 5 to the soil moisture content level of the previous day and recorded.

[0017] After conducting water consumption experiments under different drought conditions at various growth stages, 31 portions of rice plants above the soil in the experimental pots were randomly cut and weighed on an electronic scale to calculate the fresh weight of the plants at different growth stages. Combined with the difference in the quality of the wet soil at the beginning and end of the experiment Water volume in measuring cup Fresh weight variation coefficient and the inner surface area of ​​the potted plant Calculate the field water consumption after the change in fresh weight of introduced rice.

[0018] The daily water consumption is calculated using the water balance formula, without considering infiltration and rainfall. The specific water balance formula is as follows: in: h 1 This represents the water level (mm) in the potted plant the previous day. h 2 This represents the water level (mm) in the potted plant the following day. P Represents the rainfall (mm) during the period and P =0; C Discharge volume (mm) during the representative period and C =0; m i Irrigation volume (mm) during the time period; E The amount of water consumed in the field during the represented period (mm).

[0019] After the soil moisture content is calculated, add water to the level of the previous day and record it.

[0020] After weighing the fresh weight of the plants, the coefficient of change of fresh weight of rice under different water stress at each growth stage was calculated. The specific formula for calculating the coefficient of change of fresh weight of rice under different water stress at each growth stage is as follows: in: m i Represents the fresh weight of rice on day i (g); m s Represents the fresh weight of rice seedlings (g); T iRepresents the number of days in the i-th reproductive period (d); λ f The coefficient representing the change in fresh weight during the growth period; n represents the number of potted rice plants (i). m ag α represents the fresh weight (g) of the aboveground rice in the treatment group; α represents the ratio of the aboveground and belowground fresh weights in the control group (wherein... , The value represents the fresh weight (g) of the underground portion of the control group. Represents the fresh weight of the above-ground portion (g).

[0021] After introducing changes in rice fresh weight, the field water consumption was calculated. The specific formulas for calculating field water consumption at different growth stages and under different water stress levels are as follows: in: ET i Represents the field water consumption (mm) during the i-th growth stage; m 0 This represents the initial weight of the potting soil (g). m t t represents the soil weight of the potted plant at the end of the growth stage (g); t represents the number of days of water stress during the growth period (d). m i This represents the mass (g) of the i-th irrigation. ρ w The density of water is represented by a fixed value of 1.0 g / cm³. 3 ; S p Represents the area of ​​the potted plant (cm²) 2 ).

[0022] The study area for this embodiment was located at the Jiangxi Provincial Irrigation Experiment Center (N38°39′27.97″, E104°04′58.66″). Fresh weights of the aboveground and belowground parts of rice were measured at the following stages: tillering (TL, TM, TS, TE), jointing and booting (BL, BM, BS, BE), heading and development (FL, FM, FS, FE), milk stage (ML, MM, MS, ME), and treatments (CK, CM). The changes in fresh weight at different growth stages are shown in the table below. Table 1. Calculation of Fresh Weight Variation Coefficient at Different Growth Stages in Rice Pot Experiment Tillering stage CK 15.320 6.050 0.395 19.221 9.945 CM 7.315 2.890 8.056 4.748 TL 9.880 3.900 11.631 6.413 TM 11.240 4.440 13.531 7.296 TS 10.930 4.310 13.091 7.095 TE 8.570 3.380 9.801 5.563 Jointing and booting stage CK 86.290 27.670 0.321 92.590 53.043 CM 55.670 17.851 63.316 34.221 BL 82.535 26.466 95.221 50.735 BM 74.910 24.021 83.251 46.048 BS 60.250 19.320 64.330 37.036 BE 63.995 20.521 72.566 39.338 Heading and flowering period CK 199.310 65.420 0.328 150.770 123.166 CM 131.785 43.256 101.520 81.438 FL 164.820 54.099 109.918 101.852 FM 157.165 51.587 109.821 97.122 FS 125.570 41.216 87.216 77.597 FE 126.105 41.392 82.981 77.928 milk maturity period CK 231.310 77.489 0.335 44.069 143.694 CM 157.166 52.636 34.761 97.635 ML 187.255 62.730 31.066 116.326 MM 179.520 60.139 30.907 111.521 MS 142.210 47.627 23.051 88.344 ME 129.375 53.927 15.805 80.370 like Figures 2-7 As shown in the figure, an embodiment of the present invention provides a method for determining the water consumption of experimental rice. The determination steps are as follows: Before conducting water consumption tests at different growth stages (tillering stage, jointing and booting stage, heading and flowering stage, and milk stage) with varying degrees of drought (soil moisture content of 70% in mild drought, 60% in moderate drought, 50% in severe drought, and 40% in extreme drought), rice seedlings 3 were transplanted into experimental pots 2 containing saturated moisture. Experimental pots 2 were sealed, and mudguards 1 were installed at the bottom of experimental pots 2. After transplanting, experimental pots 2 were placed in the experimental field.

[0023] When conducting water consumption experiments for different drought levels at various growth stages, after the drought level is reached, when there is a water layer on the field surface, the water level of the potted plants is measured with a steel ruler for two days before and after, and the daily water consumption is calculated using the water balance formula; when there is no water layer on the field surface, the experimental pots are placed on the electronic platform scale 4 at a fixed time every day, the weight of rice 3 and moistened soil is weighed, the soil moisture content at the fixed time is calculated, and water is added with a measuring cylinder 5 to the moisture content of the previous day and recorded.

[0024] After conducting water consumption experiments under different drought conditions at various growth stages, the above-soil portion 31 of rice plants in experimental pot 2 was randomly cut and placed on an electronic scale 6. The fresh weight of the plants was measured, and the coefficient of variation of fresh weight of rice at different growth stages was calculated. Combined with the difference in the quality of the wet soil at the beginning and end of the experiment Water volume in measuring cup Fresh weight variation coefficient and the inner surface area of ​​the potted plant Calculate the field water consumption after the change in fresh weight of introduced rice.

[0025] The growth period of rice in this experiment was divided into tillering stage (June 28th to August 2nd), jointing and booting stage (August 3rd to August 26th), heading and flowering stage (August 27th to September 7th), and milk stage (September 8th to September 20th). The growth period was [number of days missing]. T i The drought days were 36, 24, 11, and 12 days respectively, representing the number of drought days in this experiment. n After 3 days, the inner surface area of ​​the potted plant was 1200.0. cm 2 The coefficients of change of fresh weight of rice at each growth stage are shown in Table 1. The amount of water per measuring cup at each growth stage ( m i The difference between the initial and final wet soil mass () and the initial and final wet soil mass () m 0- m t As shown in Table 2 below: Table 2. Irrigation amount and initial and final soil moisture quality differences at different growth stages in a rice pot experiment. Using the rice tillering stage as the calculation period, calculations were performed separately for the control treatment (CK) and the drought treatment (CM), given the initial conditions. T i=36 d, t =3 d, S p =1200 cm 2 According to Tables 1-2, λ f-ck It is 9.945, λ f-cm It is 4.748, ( m 0 -m t ) ck It weighs 10.094 kg. m 0 -m t ) cm It weighs 5.378 kg. m i ) ck It weighs 51.920 kg. m i ) cm The weight is 35.781 kg. Substituting these known conditions into the formula, we can calculate the result: Based on the above calculation results, the water consumption during the tillering stage for the control treatment (CK) and the drought treatment (CM) is 516.777 mm and 342.989 mm, respectively. Using the same calculation method, the remaining growth stage parameters are substituted into the formula to calculate the water consumption. The calculation results are shown in Table 3. Table 3. Calculation results of water consumption during the growth period of rice in a pot experiment. CK 516.78 565.80 280.70 227.50 CM 342.99 480.40 215.00 178.60 TL 403.80 546.60 312.90 212.00 TM 398.30 536.00 268.90 207.30 TS 396.20 545.50 243.40 217.30 TE 362.90 526.60 230.90 226.00 BL 485.30 529.00 269.10 215.30 BM 476.90 496.70 260.10 223.20 BS 487.20 494.40 253.70 213.00 BE 536.90 446.30 236.60 234.20 FL 521.40 491.10 237.20 208.30 FM 522.10 476.00 223.90 217.30 FS 516.60 445.90 198.90 195.30 FE 490.9 431.90 212.20 191.20 ML 487.50 556.90 278.80 202.50 MM 512.70 566.60 266.80 196.50 MS 509.10 578.40 256.60 186.80 ME 512.10 575.40 258.50 183.80 The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for determining the water consumption of experimental rice, characterized in that, Includes the following steps: To determine whether rice experimental pots have a water layer; When there is no water layer in the rice experimental pots: Obtain the initial soil moisture content at the beginning of the rice growth stage; irrigate the rice at different growth stages to keep the soil moisture content at fixed times every day consistent with the initial soil moisture content, and record the irrigation amount at fixed times every day to calculate the irrigation amount at different growth stages. At the end of the rice growth stage, the above-ground parts of the rice plant are harvested and weighed, and the underground parts are also weighed. The fresh weight variation coefficient of rice at different growth stages is calculated using an improved formula. The improved formula for the fresh weight variation coefficient of rice is as follows: in: λ f The coefficient representing the change in fresh weight of rice during its growth stage; n represents the number of potted rice plants. m ag The above-ground fresh weight of rice in the representative treatment group; m s Represents the fresh weight of rice seedlings; This represents the ratio of fresh weight of rice in the upper and lower parts of the control group. , This represents the fresh weight of the underground portion in the control group. Represents the fresh weight of the above-ground portion; Based on irrigation volume and rice fresh weight variation coefficient at different growth stages, the water consumption of rice at different growth stages is calculated using an improved rice water consumption formula; the improved rice water consumption formula is as follows: in: ET i Represents the field water consumption during the i-th growth stage; m 0 represents the initial weight of the potting soil; m t The soil weight of the potted plant indicates the end of its growth stage. t Represents the number of days of water stress during the reproductive stage; m i This represents the amount of water injected during the i-th reproductive stage; T i Represents the number of days in the i-th reproductive period; ρ w Represents the density of water; S p This represents the area of ​​the potted plant.

2. The method for determining the water consumption of experimental rice according to claim 1, characterized in that, Also includes: When there is a water layer in the rice experimental pot: Obtain the water level in the test basin at the same time point on the previous and following days; Based on the water levels of the previous and following days, the water consumption of rice on the following day is obtained through the water balance formula, and the water consumption of rice at different growth stages is calculated. The water balance formula is as follows: in: h 1 This represents the water level in the potted plant from the previous day; h 2 This represents the water level in the potted plant the following day. P Represents rainfall during a specific period; when there is no rainfall... P =0; C represents drainage volume, when there is no drainage. C =0; m i Represents the amount of water poured in; E This represents the amount of water consumed by the rice planted the following day.

3. The method for determining the water consumption of experimental rice according to claim 1, characterized in that, The process of determining whether a rice experimental pot has a water layer includes the following steps: Select multiple rice plants of the same variety and place them in an experimental pot; During the growth period experiment, observe whether there is a water layer in the rice experimental pots.

4. The method for determining the water consumption of experimental rice according to claim 1, characterized in that, The above-ground and underground parts of the rice were weighed using an electronic scale with an accuracy of 0.0001g, and the weight of the potted plant and the soil inside the potted plant were weighed using an electronic scale with an accuracy of 0.1g.

5. The method for determining the water consumption of experimental rice according to claim 1, characterized in that, The amount of water injected at different stages of growth was measured using a measuring cup, and the amount of water was converted into mass after taking a fixed value based on the density of water.

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