CN113094630A - Method for estimating relative yield of seed cotton based on air porosity - Google Patents

Abstract

A relative yield estimation method of seed cotton based on air porosity relates to a relative yield estimation method of crops based on air porosity, and belongs to the cross field of soil science-crop cultivation and tilth. The invention aims to solve the technical problem that the existing method can not quantitatively characterize the influence of soil physical properties on the growth and yield of crops, and the method comprises the following steps: when the upper limit effective aeration point of the soil irrigation management water is theta_afp＝θ_sRelative yield of seed cotton and soil air permeability (θ) at-0.1_apThe difference between the total porosity of the soil and the field water capacity) is as follows: y is 4000 x theta_ap-120, wherein Y is relative yield (%) of seed cotton, θ_apPorosity (cm) for soil aeration³cm^–3). The invention provides a method for effectively ventilating point theta_afp＝θ_sAnd-0.1) a calculation formula of the relative yield of cotton based on the ventilation porosity of the soil at the upper irrigation limit, and solves the problem that the physical properties of the soil influence the quantitative evaluation of the crop yield.

Description

Method for estimating relative yield of seed cotton based on air porosity

Technical Field

The invention relates to a method for estimating relative crop yield based on ventilation porosity, and belongs to the field of intersection of soil science-crop cultivation and tilth.

Background

Physical properties of soil are one of the important factors affecting crop growth and yield. However, how to quantitatively characterize the influence of soil physical properties on crop growth and yield has been a key issue that has not been solved by relevant research.

Disclosure of Invention

The invention aims to solve the technical problem that the influence of soil physical properties on crop growth and yield cannot be quantitatively represented by the conventional method, and provides a method for estimating the relative yield of seed cotton based on air permeability.

The soil air permeability is one of the key factors influencing the growth and yield of crops, and in order to ensure sufficient air permeability, the air permeability porosity (the difference between the total porosity of the soil and the porosity corresponding to the field water holding capacity) of the soil is higher than 0.1cm³ cm^–3If the air permeability is less than 0.1cm³ cm^–3The water capacity (theta) in the field cannot be maintained during irrigation_fc) The upper limit is 0.1cm of air vent³cm^–3The corresponding soil moisture content (effective aeration point) is the upper irrigation limit.

The method for estimating the relative yield of the seed cotton based on the ventilation porosity comprises the following steps:

when the upper limit effective aeration point of the soil irrigation management water is theta_afp＝θ_sRelative yield of seed cotton and soil air permeability (θ) at-0.1_apThe difference between the total porosity of the soil and the field water capacity) is as follows:

Y＝4000×θ_ap-120 (1)

wherein Y is relative yield (%) of seed cotton and theta_apPorosity (cm) for soil aeration³cm^–3) The calculation formula is as follows:

θ_ap＝θ_s-θ_fc (2)

in the formula, theta_sTotal porosity (cm) of soil³cm^–3)，θ_fcIs the field water holding capacity (cm)³cm^–3)。

The invention provides a method for effectively ventilating point theta_afp＝θ_sAnd-0.1) a calculation formula of the relative yield of cotton based on the ventilation porosity of the soil at the upper irrigation limit, and solves the problem that the physical properties of the soil influence the quantitative evaluation of the crop yield.

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 estimating the relative yield of the seed cotton based on the air porosity comprises the following steps:

when the upper limit effective aeration point of the soil irrigation management water is theta_afp＝θ_sAt-0.1, the relation equation of the relative yield of the seed cotton and the ventilation porosity of the soil is as follows:

Y＝4000×θ_ap-120 (1)

wherein Y is relative yield (%) of seed cotton and theta_apPorosity (cm) for soil aeration³cm^–3) The calculation formula is as follows:

θ_ap＝θ_s-θ_fc (2)

in the formula, theta_sTotal porosity (cm) of soil³cm^–3)，θ_fcIs the field water holding capacity (cm)³cm^–3)。

The derivation of equation (1) is as follows:

expressing the soil moisture characteristic curve equation in logarithmic form, i.e.

θ＝θ_s-Slog₁₀h (3)

Taking the soil water content corresponding to the water suction of 10kPa as the field water capacity (theta)_fc) Then equation (3) becomes:

θ_s-θ_fc＝S (4)

combining equations (2) and (4) yields:

θ_ap＝S (5)

at the effective ventilation point (theta)_afp＝θ_s-0.1) upper limit of water for soil irrigation management, when S is 0.03, soil property deterioration is severe and relative crop yield is reduced to 0%; when S is 0.055, the crop just begins to be stressed by water and the relative yield begins to decline. Relative yield of crop and S (theta)_ap) Is linear:

Y＝A×θ_ap+B (6)

then the following equation exists:

100＝A×0.055+B (7)

0＝A×0.03+B (8)

combining equations (7), (8) yields:

A＝4000

B＝120

thus, relative crop yield and air porosity θ_apThe relational equation of (A) is as follows:

Y＝4000×θ_ap-120 (1)

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

experiment one:

in pot culture experiments, plastic barrels with the diameter of 25cm and the depth of 30cm are used, dry soil is filled in the barrels, the thickness of soil layers is 25cm, 4 cotton plants are planted in each barrel, and the process is repeated for 3 times. The volume weight of the soil is 1.5g cm^-3、1.4g cm^-3、1.3g cm^-3、1.2g cm^-3、1.1g cm^-3. The corresponding saturated water content and field water capacity are shown in table 1. Applying nitrogen (N) and phosphorus (P) to each barrel₂O₅) Potassium (K)₂O) 2.5g, 1.0g and 2.5g, respectively. The upper limit of irrigation management is the effective aeration point (θ)_afp＝θ_s-0.1), measuring the water consumption by weighing, weighing every 2 days, and then replenishing the water to the effective aeration point (θ)_afp＝θ_s-0.1), using the formula Y ═ 4000 × θ_apAnd 120 (1) calculating. The yield profile is shown in Table 1. As can be seen from Table 1, the measured relative yields are very close to the calculated relative yields of the present invention, indicating that the method provided by the present invention is feasible.

TABLE 1

Claims (1)

1. The method for estimating the relative yield of the seed cotton based on the air porosity is characterized by comprising the following steps of:

when the upper limit effective aeration point of the soil irrigation management water is theta_afp＝θ_sRelative yield of seed cotton and soil air permeability theta at-0.1_apThe relational equation of (1) is as follows:

Y＝4000×θ_ap-120 (1)

wherein Y is relative yield of seed cotton, theta_apThe porosity of the soil is aerated.