阅读说明：本技术 预测苏打盐碱地水稻主要生育期不同耕层土壤原位ec的方法 (Method for predicting in-situ EC (soil EC) of soil in different plough layers of main growth period of rice in soda saline-alkali soil ) 是由 梁正伟 刘淼 王明明 杨昊谕 冯钟慧 于 2021-06-24 设计创作，主要内容包括：预测苏打盐碱地水稻主要生育期不同耕层土壤原位EC的方法,它涉及一种预测苏打盐碱土壤指标的方法。本发明是为了解决快速准确获取苏打盐碱地水稻主要生育期耕层原位EC费事费力的技术问题。本方法如下：一、测量得到返青期、分蘖期、拔节期、孕穗期、抽穗期、扬花期和乳熟期5cm耕层土壤原位EC；二、再将步骤一所得数值带入EC回归预测方程,即得到10cm、15cm、20cm耕层土壤原位EC。本发明通过回归方程,基于水稻主要生育期5cm耕层土壤原位EC,预测苏打盐碱地稻田相应主要生育期10cm、15cm和20cm耕层土壤原位EC。本发明测定方法省时省力,可简单快速、科学准确的获取水稻主要生育期不同耕层土壤原位EC。属于水稻生育期不同耕层土壤原位EC的预测领域。(A method for predicting in-situ EC of soil in different plough layers of main growth periods of rice in soda saline-alkali soil relates to a method for predicting indexes of soda saline-alkali soil. The method aims to solve the technical problem that the rapid and accurate acquisition of the plough layer in-situ EC in the main growth period of the rice in the soda saline-alkali soil is time-consuming and labor-consuming. The method comprises the following steps: measuring to obtain plough layer soil in-situ EC of 5cm in a seedling turning stage, a tillering stage, an elongation stage, a booting stage, a heading stage, a flowering stage and a milk stage; and secondly, substituting the numerical value obtained in the step one into an EC regression prediction equation to obtain the in-situ EC of the plough layer soil of 10cm, 15cm and 20 cm. According to the method, the in-situ EC of the plough layer soil of 10cm, 15cm and 20cm in the corresponding main growth period of the soda saline-alkali soil rice field is predicted based on the in-situ EC of the plough layer soil of 5cm in the main growth period of the rice through a regression equation. The determination method is time-saving and labor-saving, and can simply, quickly, scientifically and accurately obtain the in-situ EC of the soil in different plough layers in the main growth period of the rice. Belonging to the field of prediction of soil in-situ EC of different plough layers in the rice growth period.)

1. The method for predicting the in-situ EC of the soil in different plough layers in the main growth period of the rice in the soda saline-alkali soil is characterized by comprising the following steps of:

cleaning the surface of a metal probe of a soil in-situ EC meter by using grinding cloth, and correcting the precision of the probe by using standard liquid of the soil in-situ EC meter;

secondly, in the rice green turning stage, tillering stage, jointing stage, booting stage, heading stage, flowering stage and milk stage of soda saline-alkali soil, vertically and clockwise inserting a metal probe of a soil in-situ EC meter into soil of a plough layer of a rice field, stopping inserting the probe into the soil with the depth of 5cm, and enabling the soil to be completely and uniformly contacted with the metal surface of the probe, wherein the response time is 10-20 seconds, and the number displayed by an instrument is the measured value of the in-situ EC of the soil of the plough layer of 5cm in the green turning stage, tillering stage, jointing stage, heading stage, flowering stage and milk stage;

and thirdly, substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the green turning period obtained in the step two as an x value into an EC regression prediction equation (1):

Y＝-0.001x³+0.04x²+0.62x+0.681，R²0.965(1), namely obtaining the soil EC of 10cm plough layer in the green turning period;

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the green turning period obtained in the step two as an x value into an EC regression prediction equation (2):

Y＝-0.001x³+0.033x²+0.700x+0.748，R²obtaining the in-situ EC of the soil of the 15cm plough layer in the green turning period as 0.927 (2);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the green turning period obtained in the step two as an x value into an EC regression prediction equation (3):

Y＝-0.001x³+0.005x²+1.052x+0.324，R²obtaining the in-situ EC of the soil of the 20cm plough layer in the green turning period as 0.914 (3);

and fourthly, substituting the measured value of the in-situ EC of the soil in the plough layer of 5cm at the tillering stage obtained in the second step into an EC regression prediction equation (4) as an x value:

Y＝3.953E-05x³-0.014x²+1.272x-0.910，R²obtaining the in-situ EC of the soil of 10cm plough layer at the tillering stage as 0.992 (4);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the tillering stage obtained in the step two as an x value into an EC regression prediction equation (5):

Y＝0.980x^0.993，R²obtaining the in-situ EC of the soil of a plough layer of 15cm at the tillering stage as 0.916 (5);

substituting the EC measured value of the soil in the plough layer of 5cm at the tillering stage obtained in the step two as an x value into an EC regression prediction equation (6):

Y＝3.755E-05x³-0.013x²+1.191x-0.159，R²0.979(6), namely obtaining the in-situ EC of the soil of a 20cm plough layer at the tillering stage;

and fifthly, substituting the measured value of the soil in-situ EC of the soil of the 5cm plough layer in the jointing stage obtained in the step two as an x value into an EC regression prediction equation (7):

Y＝0.065x³+0.508x²–0.521x+1.882，R²obtaining the soil in-situ EC of 10cm plough layer in the jointing stage when the yield is 0.488 (7);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the jointing stage obtained in the step two into an EC regression prediction equation (8) as an x value:

Y＝-0.027x³+0.161x²+0.190x+1.916，R²obtaining the soil in-situ EC of 15cm plough layer soil in the jointing stage when the soil is 0.131 (8);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the jointing stage obtained in the step two into an EC regression prediction equation (9) as an x value:

Y＝0.057x³-0.546x²+2.495x-0.817，R²0.031(9), namely getting the soil in-situ EC of 20cm plough layer in jointing stage;

and sixthly, substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the booting stage obtained in the step two as an x value into an EC regression prediction equation (10):

Y＝0.005x³-0.135x²+0.853x+2.021，R²obtaining the in-situ EC of the soil of 10cm plough layer in the booting stage as 0.590 (10);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the booting stage obtained in the step two into an EC regression prediction equation (11) as an x value:

Y＝2.105x^0.434，R²obtaining the in-situ EC of the soil in the plough layer of 15cm in the booting stage, namely 0.158 (11);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the booting stage obtained in the step two into an EC regression prediction equation (12) as an x value:

Y＝0.314x³–3.076x²+9.856x-6.375，R²0.069(12), namely the in-situ EC of the soil of the 20cm plough layer in the booting stage；

And seventhly, substituting the in-situ EC measured value of the soil in the plough layer of 5cm in the heading stage obtained in the step two as an x value into an EC regression prediction equation (13):

Y＝-0.196x³+1.500x²-2.897x+3.786，R²obtaining the in-situ EC of the soil of 10cm plough layer in the heading stage when the yield is 0.450 (13);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the heading stage obtained in the step two as an x value into an EC regression prediction equation (14):

Y＝-0.353x³+2.287x²-3.978x+4.321，R²obtaining the in-situ EC of the soil in the plough layer of 15cm in the heading stage when the yield is 0.188 (14);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the heading stage obtained in the step two as an x value into an EC regression prediction equation (15):

Y＝-0.173x³+0.996x²-0.956x+2.611，R²obtaining 20cm plough layer in-situ soil EC in heading period as 0.082 (15);

and eighthly, substituting the in-situ EC measured value of the soil of the 5cm plough layer at the flowering stage obtained in the step two into an EC regression prediction equation (16) as an x value:

Y＝1.350x^0.768，R²0.598(16), namely obtaining the in-situ EC of the 10cm plough layer soil in the flowering period;

substituting the in-situ EC measured value of the soil of 5cm plough layer of flowering phase obtained in the step two into an EC regression prediction equation (17) as an x value:

Y＝1.444x^0.765，R²0.433(17), namely obtaining the in-situ EC of the soil of a 15cm plough layer in the flowering period;

substituting the in-situ EC measured value of the soil of 5cm plough layer of the flowering phase obtained in the step two into an EC regression prediction equation (18) as an x value:

Y＝0.156x³-1.511x²+5.330x-2.902，R²0.336(18), namely obtaining the in-situ EC of 20cm plough layer soil in the flowering period;

and ninthly, substituting the measured value of the soil in-situ EC of the plough layer of 5cm in the milk stage obtained in the step two as the x value into an EC regression prediction equation (19):

Y＝-0.095x³+0.893x²-1.759x+3.150，R²0.635(19), i.e.Obtaining the soil in-situ EC of 10cm plough layer soil in the milk stage;

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the milk stage obtained in the step two as an x value into an EC regression prediction equation (20):

Y＝-0.068x³+0.636x²-1.263x+3.383，R²0.384(20), namely the in-situ EC of the soil of the plough layer of 15cm in the milk stage is obtained;

substituting the in-situ EC measured value of soil of 5cm plough layer in the milk stage obtained in the step two as an x value into an EC regression prediction equation (21):

Y＝-0.117x³+1.028x²-2.344x+4.725，R²and (3) obtaining the in-situ EC of the soil of the 20cm plough layer in the milk stage when the yield is 0.170 (21).

Technical Field

The invention relates to a method for predicting indexes of soda saline-alkali soil.

Background

The Songnen plain is one of three concentrated regions of soda saline-alkali soil in the world, and the soda saline-alkali soil is composed of NaHCO₃With Na₂CO₃Mainly has pH more than 8.5, is strong alkaline, has alkalinization degree more than 70 percent, has poor physicochemical property, large treatment difficulty, long time and slow effect. Practice proves that the development of the rice seeds is an effective way for improving and utilizing the soda saline-alkali land. The soil conductivity (EC) is an index for measuring water-soluble salt in soil and is an important reference for judging the light and heavy degree of soda saline-alkali soil. Meanwhile, the soil EC of different plough layers of the rice is an important factor for judging whether the salt ions in the soda saline-alkali soil limit the growth of the rice and influence the absorption and utilization of mineral nutrition. Therefore, monitoring of soil salinity of different plough layers of the main growth period of the rice in soda saline-alkali soil is an essential measure. For a long time, most of saline-alkali soil plough layer EC measurement is carried out by taking a soil sample and air-drying the soil, and then preparing a soil leaching solution for indoor measurement, and along with the development of the technology, the soil in-situ EC is taken as a portable soil salinity measuring instrument for wide application. Before the in-situ EC meter is used for testing, the surface of a metal probe of the in-situ EC meter is firstly cleaned by an abrasive cloth so as to prevent the measurement precision of the in-situ EC meter from being influenced. When the method is used for measuring the soil EC of different plough layers, after the in-situ EC of soil of one plough layer depth is measured, the soil on the surface of a metal probe of the EC meter needs to be cleaned in time, and the in-situ EC of the soil of other depths is measured after the EC meter is washed by distilled water. However, the physical and chemical properties of the soda saline-alkali soil are poor, the heavy soil is adhered to the surface of the probe, the cleaning process is troublesome and labor-consuming, and the rapid and accurate acquisition of the in-situ EC of the soil in different plough layers of the main growth period of the rice in the soda saline-alkali soil has certain difficulty.

Disclosure of Invention

The invention aims to solve the technical problem that the rapid and accurate acquisition of the in-situ EC of the soil in different plough layers of the main growth period of the rice in the soda saline-alkali soil is time-consuming and labor-consuming, and provides a method for predicting the in-situ EC of the soil in different plough layers of the main growth period of the rice in the soda saline-alkali soil.

The method for predicting different plough layers EC of the main growth period of the rice in the soda saline-alkali soil is carried out according to the following steps:

cleaning the surface of a metal probe of a soil in-situ EC meter by using grinding cloth, and correcting the precision of the probe by using standard liquid of the soil in-situ EC meter;

secondly, in the rice green turning stage, tillering stage, jointing stage, booting stage, heading stage, flowering stage and milk stage of soda saline-alkali soil, vertically and clockwise inserting a metal probe of a soil in-situ EC meter into soil of a plough layer of a rice field, stopping inserting the probe into the soil with the depth of 5cm, and enabling the soil to be completely and uniformly contacted with the metal surface of the probe, wherein the response time is 10-20 seconds, and the number displayed by an instrument is the measured value of the EC of the soil of the plough layer of 5cm in the green turning stage, tillering stage, jointing stage, heading stage, flowering stage and milk stage;

and thirdly, substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the green turning period obtained in the step two as an x value into an EC regression prediction equation (1):

Y＝-0.001x³+0.04x²+0.62x+0.681，R²obtaining the in-situ EC of the soil of 10cm plough layer in the green turning period as 0.965 (1);

substituting the EC measured value of the soil in the 5cm plough layer of the green turning period obtained in the step two as an x value into an EC regression prediction equation (2):

Y＝-0.001x³+0.033x²+0.700x+0.748，R²obtaining the in-situ EC of the soil of the 15cm plough layer in the green turning period as 0.927 (2);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the green turning period obtained in the step two as an x value into an EC regression prediction equation (3):

Y＝-0.001x³+0.005x²+1.052x+0.324，R²obtaining the in-situ EC of the soil of the 20cm plough layer in the green turning period as 0.914 (3);

and fourthly, substituting the measured value of the in-situ EC of the soil in the plough layer of 5cm at the tillering stage obtained in the second step into an EC regression prediction equation (4) as an x value:

Y＝3.953E-05x³-0.014x²+1.272x-0.910，R²obtaining the in-situ EC of the soil of 10cm plough layer at the tillering stage as 0.992 (4);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the tillering stage obtained in the step two as an x value into an EC regression prediction equation (5):

Y＝0.980x⁰ _. ⁹⁹³，R²obtaining the in-situ EC of the soil of a plough layer of 15cm at the tillering stage as 0.916 (5);

substituting the EC in-situ measured value of the soil EC of the 5cm plough layer at the tillering stage obtained in the step two as an x value into an EC regression prediction equation (6):

Y＝3.755E-05x³-0.013x²+1.191x-0.159，R²0.979(6), namely obtaining the in-situ EC of the soil of a 20cm plough layer at the tillering stage;

and fifthly, substituting the measured value of the soil in-situ EC of the soil of the 5cm plough layer in the jointing stage obtained in the step two as an x value into an EC regression prediction equation (7):

Y＝0.065x³+0.508x²–0.521x+1.882，R²obtaining the soil in-situ EC of 10cm plough layer in the jointing stage when the yield is 0.488 (7);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the jointing stage obtained in the step two into an EC regression prediction equation (8) as an x value:

Y＝-0.027x³+0.161x²+0.190x+1.916，R²obtaining the soil in-situ EC of 15cm plough layer soil in the jointing stage when the soil is 0.131 (8);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the jointing stage obtained in the step two into an EC regression prediction equation (9) as an x value:

Y＝0.057x³-0.546x²+2.495x-0.817，R²0.031(9), namely getting the soil in-situ EC of 20cm plough layer in jointing stage;

and sixthly, substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the booting stage obtained in the step two as an x value into an EC regression prediction equation (10):

Y＝0.005x³-0.135x²+0.853x+2.021，R²obtaining the in-situ EC of the soil of 10cm plough layer in the booting stage as 0.590 (10);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the booting stage obtained in the step two into an EC regression prediction equation (11) as an x value:

Y＝2.105x⁰ _. ⁴³⁴，R²obtaining the in-situ EC of the soil in the plough layer of 15cm in the booting stage, namely 0.158 (11);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the booting stage obtained in the step two into an EC regression prediction equation (12) as an x value:

Y＝0.314x³–3.076x²+9.856x-6.375，R²obtaining the soil in-situ EC of 20cm plough layer soil in the booting stage as 0.069 (12);

and seventhly, substituting the in-situ EC measured value of the soil in the plough layer of 5cm in the heading stage obtained in the step two as an x value into an EC regression prediction equation (13):

Y＝-0.196x³+1.500x²-2.897x+3.786，R²obtaining the in-situ EC of the soil of 10cm plough layer in the heading stage when the yield is 0.450 (13);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the heading stage obtained in the step two as an x value into an EC regression prediction equation (14):

Y＝-0.353x³+2.287x²-3.978x+4.321，R²obtaining the in-situ EC of the soil in the plough layer of 15cm in the heading stage when the yield is 0.188 (14);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the heading stage obtained in the step two as an x value into an EC regression prediction equation (15):

Y＝-0.173x³+0.996x²-0.956x+2.611，R²obtaining the in-situ EC of the soil of a 20cm plough layer in the heading stage as 0.082 (15);

and eighthly, substituting the in-situ EC measured value of the soil of the 5cm plough layer at the flowering stage obtained in the step two into an EC regression prediction equation (16) as an x value:

Y＝1.350x⁰ _. ⁷⁶⁸，R²0.598(16), namely obtaining the in-situ EC of the 10cm plough layer soil in the flowering period;

substituting the in-situ EC measured value of the soil of 5cm plough layer of flowering phase obtained in the step two into an EC regression prediction equation (17) as an x value:

Y＝1.444x⁰ _. ⁷⁶⁵，R²0.433(17), namely obtaining the in-situ EC of the soil of a 15cm plough layer in the flowering period;

substituting the in-situ EC measured value of the soil of 5cm plough layer of the flowering phase obtained in the step two into an EC regression prediction equation (18) as an x value:

Y＝0.156x³-1.511x²+5.330x-2.902，R²0.336(18), namely obtaining the in-situ EC of 20cm plough layer soil in the flowering period;

and ninthly, substituting the measured value of the soil in-situ EC of the plough layer of 5cm in the milk stage obtained in the step two as the x value into an EC regression prediction equation (19):

Y＝-0.095x³+0.893x²-1.759x+3.150，R²0.635(19), namely obtaining the in-situ EC of the soil of a 10cm plough layer in the milk stage;

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the milk stage obtained in the step two as an x value into an EC regression prediction equation (20):

Y＝-0.068x³+0.636x²-1.263x+3.383，R²0.384(20), namely the in-situ EC of the soil of the plough layer of 15cm in the milk stage is obtained;

substituting the in-situ EC measured value of soil of 5cm plough layer in the milk stage obtained in the step two as an x value into an EC regression prediction equation (21):

Y＝-0.117x³+1.028x²-2.344x+4.725，R²and (3) obtaining the in-situ EC of the soil of the 20cm plough layer in the milk stage when the yield is 0.170 (21).

According to the method, the in-situ EC of the plough layer soil of 10cm, 15cm and 20cm in the corresponding main growth period of the soda saline-alkali soil rice field can be predicted based on the in-situ EC of the plough layer soil of 5cm in the main growth period of the rice through a regression equation.

The determination method is time-saving and labor-saving, and can simply, quickly, scientifically and accurately obtain the in-situ EC of the soil in different plough layers in the main growth period of the rice.

Drawings

FIG. 1 is a correlation graph of the predicted value and the measured value of the in-situ EC of the soil of a plough layer of 10cm in the rice green turning period in the soda saline-alkali soil in the first experiment;

FIG. 2 is a correlation graph of the predicted value and the measured value of the in-situ EC of the soil in the plough layer of 15cm at the rice green turning stage in the soda saline-alkali soil in the first experiment;

FIG. 3 is a correlation graph of the predicted value and the measured value of the in-situ EC of the soil in the 20cm plough layer of the rice at the seedling turning stage in the soda saline-alkali soil in the first experiment;

FIG. 4 is a correlation graph of the predicted value and the measured value of the in-situ EC of the plough layer soil of 10cm at the tillering stage of the rice in the soda saline-alkali soil in the second experiment;

FIG. 5 is a correlation graph of the predicted value and the measured value of the in-situ EC of the plough layer soil of 10cm at the tillering stage of the rice in the soda saline-alkali soil in the second experiment;

FIG. 6 is a correlation graph of the predicted value and the measured value of the in-situ EC of the plough layer soil of 10cm at the tillering stage of the rice in the soda saline-alkali soil in the second experiment.

Detailed Description

The technical solution of the present invention is not limited to the following specific embodiments, but includes any combination of the specific embodiments.

The first embodiment is as follows: the method for predicting the in-situ EC of the soil in different plough layers of the main growth period of the rice in the soda saline-alkali soil is carried out according to the following steps:

cleaning the surface of a metal probe of a soil in-situ EC meter by using grinding cloth, and correcting the precision of the probe by using standard liquid of the soil in-situ EC meter;

secondly, in the rice green turning stage, tillering stage, jointing stage, booting stage, heading stage, flowering stage and milk stage of soda saline-alkali soil, vertically and clockwise inserting a metal probe of a soil in-situ EC meter into soil of a plough layer of a rice field, stopping inserting the probe into the soil with the depth of 5cm, and enabling the soil to be completely and uniformly contacted with the metal surface of the probe, wherein the response time is 10-20 seconds, and the number displayed by an instrument is the measured value of the in-situ EC of the soil of the plough layer of 5cm in the green turning stage, tillering stage, jointing stage, heading stage, flowering stage and milk stage;

performing correlation analysis on the in-situ EC of 5cm plough layer soil in a rice green turning stage, a tillering stage, an elongation stage, a booting stage, a heading stage, a flowering stage and a milk stage and the in-situ EC of 10cm, 15cm and 20cm plough layer soil in corresponding growth stages by adopting SPSS software;

respectively constructing regression equations for the in-situ EC of 5cm plough layer soil in the rice green turning stage, the tillering stage, the jointing stage, the booting stage, the heading stage, the flowering stage and the milk stage and the in-situ EC of 10cm plough layer soil, 15cm plough layer soil and 20cm plough layer soil in the corresponding growth stages by adopting SPSS software;

and thirdly, substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the green turning period obtained in the second step into an EC regression prediction equation (1) as an x value (obtained according to 834 sample measured values):

Y＝-0.001x³+0.04x²+0.62x+0.681，R²obtaining the in-situ EC of the soil of 10cm plough layer in the green turning period as 0.965 (1);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the green turning period obtained in the step two into an EC regression prediction equation (2) as an x value (obtained according to 834 sample measured values):

Y＝-0.001x³+0.033x²+0.700x+0.748，R²obtaining the in-situ EC of the soil of the 15cm plough layer in the green turning period as 0.927 (2);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the green turning period obtained in the step two as an x value into an EC regression prediction equation (3) (obtained according to 834 sample measured values):

Y＝-0.001x³+0.005x²+1.052x+0.324，R²obtaining the in-situ EC of the soil of the 20cm plough layer in the green turning period as 0.914 (3);

and fourthly, substituting the in-situ EC measured value of the soil in the plough layer of 5cm at the tillering stage obtained in the second step into an EC regression prediction equation (4) as an x value (obtained according to actual measured values of 1080 samples):

Y＝3.953E-05x³-0.014x²+1.272x-0.910，R²obtaining the in-situ EC of the soil of 10cm plough layer at the tillering stage as 0.992 (4);

substituting the in-situ EC measured value of the soil in the plough layer of 5cm at the tillering stage obtained in the step two as an x value into an EC regression prediction equation (5) (obtained according to actual measured values of 1080 samples):

Y＝0.980x⁰ _. ⁹⁹³，R²obtaining the in-situ EC of the soil of a plough layer of 15cm at the tillering stage as 0.916 (5);

substituting the in-situ EC measured value of the soil in the plough layer of 5cm at the tillering stage obtained in the step two as an x value into an EC regression prediction equation (6) (obtained according to actual measured values of 1080 samples):

Y＝3.755E-05x³-0.013x²+1.191x-0.159，R²0.979(6), namely obtaining the in-situ EC of the soil of a 20cm plough layer at the tillering stage;

and fifthly, substituting the in-situ EC measured value of the soil of the 5cm plough layer in the jointing stage obtained in the step two as an x value into an EC regression prediction equation (7) (obtained according to 460 sample measured values):

Y＝0.065x³+0.508x²–0.521x+1.882，R²obtaining the soil in-situ EC of 10cm plough layer in the jointing stage when the yield is 0.488 (7);

substituting the EC measured value of the soil in situ of the 5cm plough layer soil in the jointing stage obtained in the step two into an EC regression prediction equation (8) as an x value (obtained according to the actual measured values of 460 samples):

Y＝-0.027x³+0.161x²+0.190x+1.916，R²obtaining the soil in-situ EC of 15cm plough layer soil in the jointing stage when the soil is 0.131 (8);

substituting the EC measured value of the soil in situ of the 5cm plough layer soil in the jointing stage obtained in the step two into an EC regression prediction equation (9) as an x value (obtained according to the actual measured values of 460 samples):

Y＝0.057x³-0.546x²+2.495x-0.817，R²0.031(9), namely getting the soil in-situ EC of 20cm plough layer in jointing stage;

and sixthly, substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the booting stage obtained in the step two as an x value into an EC regression prediction equation (10) (obtained according to actual measured values of 320 samples):

Y＝0.005x³-0.135x²+0.853x+2.021，R²obtaining the in-situ EC of the soil of 10cm plough layer in the booting stage as 0.590 (10);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the booting stage obtained in the step two as an x value into an EC regression prediction equation (11) (obtained according to actual measured values of 320 samples):

Y＝2.105x⁰ _. ⁴³⁴，R²obtaining the in-situ EC of the soil in the plough layer of 15cm in the booting stage, namely 0.158 (11);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the booting stage obtained in the step two as an x value into an EC regression prediction equation (12) (obtained according to actual measured values of 320 samples):

Y＝0.314x³–3.076x²+9.856x-6.375，R²obtaining the soil in-situ EC of 20cm plough layer soil in the booting stage as 0.069 (12);

and seventhly, substituting the in-situ EC value of the soil of the plough layer of 5cm in the heading stage obtained in the step two as an x value into an EC regression prediction equation (13) (obtained according to measured values of 320 samples):

Y＝-0.196x³+1.500x²-2.897x+3.786，R²obtaining the in-situ EC of the soil of 10cm plough layer in the heading stage when the yield is 0.450 (13);

substituting the in-situ EC measured value of the soil in the plough layer of 5cm in the heading stage obtained in the step two as an x value into an EC regression prediction equation (14) (obtained according to actual measured values of 320 samples):

Y＝-0.353x³+2.287x²-3.978x+4.321，R²obtaining the in-situ EC of the soil in the plough layer of 15cm in the heading stage when the yield is 0.188 (14);

substituting the in-situ EC measured value of the soil in the plough layer of 5cm in the heading stage obtained in the step two as an x value into an EC regression prediction equation (15) (obtained according to actual measured values of 320 samples):

Y＝-0.173x³+0.996x²-0.956x+2.611，R²obtaining the in-situ EC of the soil of a 20cm plough layer in the heading stage as 0.082 (15);

and eighthly, substituting the in-situ EC measured value of the soil of the 5cm plough layer at the flowering stage obtained in the step two into an EC regression prediction equation (16) as an x value (obtained according to the actual measured values of 320 samples):

Y＝1.350x⁰ _. ⁷⁶⁸，R²0.598(16), namely obtaining the in-situ EC of the 10cm plough layer soil in the flowering period;

substituting the in-situ EC measured value of the soil of 5cm plough layer at the flowering stage obtained in the step two into an EC regression prediction equation (17) as an x value (obtained according to the actual measured values of 320 samples):

Y＝1.444x⁰ _. ⁷⁶⁵，R²0.433(17), namely obtaining the in-situ EC of the soil of a 15cm plough layer in the flowering period;

substituting the in-situ EC measured value of the soil of 5cm plough layer at the flowering stage obtained in the step two into an EC regression prediction equation (18) as an x value (obtained according to the actual measured values of 320 samples):

Y＝0.156x³-1.511x²+5.330x-2.902，R²0.336(18), namely obtaining the in-situ EC of 20cm plough layer soil in the flowering period;

and ninthly, substituting the in-situ EC measured value of the soil in the plough layer of 5cm in the milk stage obtained in the step two as the x value into an EC regression prediction equation (19) (obtained according to the measured values of 250 samples):

Y＝-0.095x³+0.893x²-1.759x+3.150，R²0.635(19), namely obtaining the in-situ EC of the soil of a 10cm plough layer in the milk stage;

substituting the in-situ EC measured value of soil in the plough layer of 5cm in the milk stage obtained in the step two as an x value into an EC regression prediction equation (20) (obtained according to the measured values of 250 samples):

Y＝-0.068x³+0.636x²-1.263x+3.383，R²0.384(20), namely the in-situ EC of the soil of the plough layer of 15cm in the milk stage is obtained;

substituting the in-situ EC measured value of soil in the plough layer of 5cm in the milk stage obtained in the step two as an x value into an EC regression prediction equation (21) (obtained according to the measured values of 250 samples):

Y＝-0.117x³+1.028x²-2.344x+4.725，R²and (3) obtaining the in-situ EC of the soil of the 20cm plough layer in the milk stage when the yield is 0.170 (21).

The following experiments are adopted to verify the effect of the invention:

experiment one:

in 2019, the plough layer soil of the rice green turning period in the soda saline-alkali soil of the national field surgery observation research station of the Jilin Daan farmland ecosystem is predicted.

The method for predicting different plough layers EC of the main growth period of the rice in the soda saline-alkali soil is carried out according to the following steps:

cleaning the surface of a metal probe of a soil in-situ EC meter by using grinding cloth, and correcting the precision of the probe by using standard liquid of the soil in-situ EC meter;

secondly, in the rice green turning period of the soda saline-alkali soil, vertically and clockwise inserting a metal probe of a soil in-situ EC meter into soil of a plough layer of a rice field, stopping inserting the probe into the soil at a depth of 5cm, and enabling the soil to be completely and uniformly contacted with the metal surface of the probe, wherein the response time is 10-20 seconds, the number displayed by an instrument is the measured value of the in-situ EC of the soil of the plough layer of 5cm in the green turning period, and the in-situ EC is 9.10, 8.94 and 9.59 mS/cm;

and thirdly, substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the green turning period obtained in the step two as an x value into an EC regression prediction equation (1):

Y＝-0.001x³+0.04x²+0.62x+0.681，R²the in-situ EC of the soil of the 10cm plough layer in the green turning period is 8.88, 8.71 and 9.42mS/cm respectively as 0.965 (1);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the green turning period obtained in the step two as an x value into an EC regression prediction equation (2):

Y＝-0.001x³+0.033x²+0.700x+0.748，R²the in-situ EC of the soil of the 15cm plough layer in the green turning period is respectively 9.10, 8.93 and 9.61mS/cm, namely 0.927 (2);

substituting the in-situ EC measured value of the soil of the 5cm plough layer in the green turning period obtained in the step two as an x value into an EC regression prediction equation (3):

Y＝-0.001x³+0.005x²+1.052x+0.324，R²and (3), namely the in-situ EC of the soil of the 20cm plough layer in the green turning period is 9.56, 9.41 and 9.99mS/cm respectively.

Further applying regression equation to fit measured values and predicted values of soil in situ EC of plough layer of 10cm, 15cm and 20cm in the green turning period (figure 1-figure 3), wherein the goodness of fit is R respectively²＝0.981，R²＝0.962，R²The equation is 0.952(P is less than 0.0001), which shows that the equation has statistical significance, and the method realizes the prediction of the soil in-situ EC of the plough layer soil of 10cm, 15cm and 20cm in the field green-turning period of the soda saline-alkali soil.

Experiment two:

in 2019, the tilth soil of the rice tillering stage of soda saline-alkali soil of the national field surgery observation and research station of Jilin Daan farmland ecosystem is predicted.

The method for predicting different plough layers EC of the main growth period of the rice in the soda saline-alkali soil is carried out according to the following steps:

cleaning the surface of a metal probe of a soil in-situ EC meter by using grinding cloth, and correcting the precision of the probe by using standard liquid of the soil in-situ EC meter;

secondly, in the tillering stage of the rice in the soda saline-alkali soil, vertically and clockwise inserting a metal probe of a soil in-situ EC meter into the soil of a plough layer of the rice field, stopping inserting the probe into the soil at a depth of 5cm, and enabling the soil to be completely and uniformly contacted with the metal surface of the probe, wherein the response time is 10-20 seconds, the number displayed by an instrument is the measured value of the in-situ EC of the soil of the plough layer of 5cm in the green turning stage, and the in-situ EC is respectively 4.43, 3.53 and 2.66 mS/cm;

and thirdly, substituting the measured value of the soil in-situ EC of the plough layer of 5cm at the tillering stage obtained in the second step into an EC regression prediction equation (4) as an x value:

Y＝3.953E-05x³-0.014x²+1.272x-0.910，R²the in-situ EC of the soil of 10cm plough layer at the tillering stage is 4.45, 3.41 and 2.38mS/cm respectively as 0.992 (4);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the tillering stage obtained in the step two as an x value into an EC regression prediction equation (5):

Y＝0.980x⁰ _. ⁹⁹³，R²the in-situ EC of the soil in the plough layer with the tillering period of 15cm is 4.30, 3.43 and 2.59mS/cm respectively as 0.916 (5);

substituting the in-situ EC measured value of the soil of the plough layer of 5cm in the tillering stage obtained in the step two as an x value into an EC regression prediction equation (6):

Y＝3.755E-05x³-0.013x²+1.191x-0.159，R²and (6), namely the in-situ EC of the soil in the plough layer with the tillering period of 20cm is 4.87 mS/cm, 3.38 mS/cm and 2.92mS/cm respectively.

Further applying regression equation to fit measured values and predicted values of soil in situ EC of plough layers of 10cm, 15cm and 20cm at tillering stage (figure 4-figure 6), wherein goodness of fit is R respectively²＝0.992，R²＝0.457，R²The equation is 0.989(P is less than 0.0001), which shows that the equation has statistical significance, and the method realizes the prediction of the in-situ EC of the plough layer soil of 10cm, 15cm and 20cm in the tillering stage of the paddy field of the soda saline-alkali soil.