US-12619803-B2 - Method and system for calculating water-land-forage-livestock balance in family pasture by taking forage quality into account

US12619803B2US 12619803 B2US12619803 B2US 12619803B2US-12619803-B2

Abstract

The present disclosure provides a method and system for calculating water-land-forage-livestock balance in a family pasture by taking forage quality into account. The method takes a family pasture as a calculation unit and starts from a water circulation process, various types of groundwater recharges of the family pasture are calculated, and an available groundwater quantity is calculated by using an exploitable coefficient method, and undergoes water-land balance calculation with an irrigation water demand and a drinking water demand of people and livestock; and total digestible nutrients of various types of forage are used to convert each type of forage into standard hay for forage-livestock balance calculation, so as to determine a maximum supportable planting area of irrigated artificial grasslands and a maximum supportable quantity of livestock raised in the family pasture.

Inventors

Haiyuan Lu
Shanli Yang
MORIGEN
Heping Li
Jun Wang
Hexiang Zheng
Xuesong CAO
Changfu Tong
Bater Bai
Jiabin Wu
Zhiwei Ma

Assignees

Institute Of Water Resources for Pastoral Area, MWR

Dates

Publication Date: 20260505
Application Date: 20221018
Priority Date: 20220511

Claims (12)

1 . A method for adjusting water-land-forage-livestock balance in a family pasture by taking forage quality into account, comprising: S 1 : constructing a family pasture available-groundwater-supply equation and a family pasture water demand quantity equation based on area parameters of various irrigated artificial grasslands and a quantity of livestock raised; S 2 : determining a water-land balance calculation equation based on an equality constraint condition between the family pasture available-groundwater-supply equation and the family pasture water demand quantity equation; S 3 : converting various grasslands into standard hay by using total digestible nutrients of forage of various grasslands, obtaining a yield of the standard hay of the various grasslands, and constructing an available-forage-quantity equation and a forage demand quantity equation based on the yield of the standard hay of the various grasslands, the area parameters of various irrigated artificial grasslands, and the quantity of livestock raised; S 4 : determining a forage-livestock balance calculation equation based on an equality constraint condition between the available-forage-quantity equation and the forage demand quantity equation; S 5 : obtaining the area parameters of various irrigated artificial grasslands and the quantity of livestock raised by solving the simultaneous water-land balance calculation equation and forage-livestock balance calculation equation to determine a maximum supportable planting area of irrigated artificial grasslands and a maximum supportable quantity of livestock raised in the family pasture; and adjusting an actual area of the irrigated artificial grasslands and an actual quantity of the livestock raised based on the maximum supportable planting area of the irrigated artificial grasslands and the maximum supportable quantity of the livestock raised in the family pasture; wherein the converting various grasslands into standard hay by using total digestible nutrients of forage of various grasslands comprises: y si =y i ×n i η i = TDN i TDN s wherein y si is a standard hay conversion quantity (kg/hm 2 ) of various grasslands; y i is a forage yield (kg/hm 2 ) of various grasslands; n i is a standard hay conversion coefficient; TDN i is total digestible nutrients (%) of forage of various grasslands; and TDN s is total digestible nutrients (%) of temperate steppe forage which is mainly gramineous forage grass.
2 . The method for adjusting water-land-forage-livestock balance in a family pasture by taking forage quality into account according to claim 1 , wherein the family pasture available-groundwater-supply equation is: W S = R × β R = 10 3 ⁢ A × P × α p + ∑ i A i × m i × α i wherein W s isd an available-groundwater-supply (m 3 ); β is an exploitable coefficient; A is a family pasture land area (km 2 ); P is rainfall (mm); α p is an infiltration recharge coefficient of rainfall; A i is an area (hm 2 ) of various grasslands, comprising irrigated artificial grasslands and natural grasslands; m i is an irrigation quota (m 3 /hm 2 ) for various grasslands, and the natural grasslands are not irrigated, and have a quota of 0; and α i is an irrigation infiltration recharge coefficient; and the family pasture water demand quantity equation is: W R =R×m r +A i ×m i +L×m l wherein W R is a water demand quantity (m 3 ); R is a quantity of people in the family pasture; m r is a per capita drinking water quota (m 3 /person); L is a to-be-determined quantity of livestock raised (in unit of sheep); and m i is a drinking water quota for livestock (m 3 /sheep).
3 . The method for adjusting water-land-forage-livestock balance in a family pasture by taking forage quality into account according to claim 2 , wherein the water-land balance calculation equation is: W S =W R .
4 . The method for adjusting water-land-forage-livestock balance in a family pasture by taking forage quality into account according to claim 1 , wherein a calculation equation for the total digestible nutrients is: TDN =81.38+0.36 CP −0.77 ADF wherein TDN is the total digestible nutrients (%), comprising TDN i and TDN s ; CP is a content (%) of a crude protein in the forage; and ADF is a content (%) of an acid detergent fiber in the forage.
5 . The method for adjusting water-land-forage-livestock balance in a family pasture by taking forage quality into account according to claim 1 , wherein the available-forage-quantity equation is determined by using the following formula: F S = ∑ i A i × y si × d i wherein F S is an available forage quantity (kg); A i is an area (hm 2 ) of various grasslands; d i is utilization of artificial forage; d j is utilization of natural grasslands; and the forage demand quantity equation is: F R =L×D wherein F R is a forage demand quantity (kg); L is a quantity of livestock raised; and D is a forage quota for livestock raising.
6 . The method for adjusting water-land-forage-livestock balance in a family pasture by taking forage quality into account according to claim 5 , wherein the forage-livestock balance calculation equation is: F S =F R .
7 . A system for adjusting water-land-forage-livestock balance in a family pasture according to the method for adjusting water-land-forage-livestock balance in a family pasture by taking forage quality into account, comprising a processor and a memory storing program codes, wherein the processor performs the stored program codes to construct a family pasture available-groundwater-supply equation based on area parameters of various irrigated artificial grasslands; construct a family pasture water demand quantity equation based on the area parameters of various irrigated artificial grasslands and a quantity of livestock raised; determine a water-land balance calculation equation based on an equality constraint condition between the family pasture available-groundwater-supply equation and the family pasture water demand quantity equation; convert various grasslands into standard hay by using total digestible nutrients of forage of various grasslands, and obtain a yield of the standard hay of the various grasslands; construct an available-forage-quantity equation based on the yield of the standard hay of the various grasslands and the area parameters of various irrigated artificial grasslands; construct a forage demand quantity equation based on the quantity of livestock raised; determine a forage-livestock balance calculation equation based on an equality constraint condition between the available-forage-quantity equation and the forage demand quantity equation; obtain the area parameters of various irrigated artificial grasslands and the quantity of livestock raised by solving the simultaneous water-land balance calculation equation and forage-livestock balance calculation equation to determine a maximum supportable planting area of irrigated artificial grasslands and a maximum supportable quantity of livestock raised in the family pasture; and adjust an actual area of the irrigated artificial grasslands and an actual quantity of the livestock raised based on the maximum supportable planting area of the irrigated artificial grasslands and the maximum supportable quantity of the livestock raised in the family pasture; wherein the converting various grasslands into standard hay by using total digestible nutrients of forage of various grasslands comprises: y si =y 1 ×n i η i = T ⁢ D ⁢ N i T ⁢ D ⁢ N s wherein y si is a standard hay conversion quantity (kg/hm 2 ) of various grasslands; y si is a forage yield (kg/hm 2 ) of various grasslands; n i is a standard hay conversion coefficient; TDN i is total digestible nutrients (%) of forage of various grasslands; and TDN s is total digestible nutrients (%) of temperate steppe forage which is mainly gramineous forage grass.
8 . The system according to claim 7 , wherein the family pasture available-groundwater-supply equation is: W S = R × β R = 10 3 ⁢ A × P × α p + ∑ i A i × m i × α i wherein W s is an available-groundwater-supply (m 3 ); β is an exploitable coefficient; A is a family pasture land area (km 2 ); P is rainfall (mm); α p is an infiltration recharge coefficient of rainfall; A i is an area (hm 2 ) of various grasslands, comprising irrigated artificial grasslands and natural grasslands; m i is an irrigation quota (m 3 /hm 2 ) for various grasslands, and the natural grasslands are not irrigated, and have a quota of 0; and α i is an irrigation infiltration recharge coefficient; and the family pasture water demand quantity equation is: W R =R×m r +A i ×m i +L×m l wherein W R is a water demand quantity (m 3 ); R is a quantity of people in the family pasture; m r is a per capita drinking water quota (m 3 /person); L is a to-be-determined quantity of livestock raised (in unit of sheep); and m l is a drinking water quota for livestock (m 3 /sheep).
9 . The system according to claim 8 , wherein the water-land balance calculation equation is: W S =W R .
10 . The system according to claim 7 , wherein a calculation equation for the total digestible nutrients is: TDN =81.38+0.36 CP −0.77 ADF wherein TDN is the total digestible nutrients (%), comprising TDN i and TDN s ; CP is a content (%) of a crude protein in the forage; and ADF is a content (%) of an acid detergent fiber in the forage.
11 . The system according to claim 7 , wherein the available-forage-quantity equation is determined by using the following formula: F S = ∑ i A i × y si × d i wherein F S is an available forage quantity (kg); A i is an area (hm 2 ) of various grasslands; d i is utilization of artificial forage; d j is utilization of natural grasslands; and the forage demand quantity equation is: F R =L×D wherein F R is a forage demand quantity (kg); L is a quantity of livestock raised; and D is a forage quota for livestock raising.
12 . The system according to claim 11 , wherein the forage-livestock balance calculation equation is: F S =F R .

Description

CROSS REFERENCE TO RELATED APPLICATION This patent application claims the benefit and priority of Chinese Patent Application No. 202210514643.2, filed on May 11, 2022, the disclosure of which is incorporated by reference herein in its entirety as part of the present application. TECHNICAL FIELD The present disclosure relates to the technical field of mathematical model calculation, and in particular, to a method and system for calculating water-land-forage-livestock balance in a family pasture by taking forage quality into account. BACKGROUND ART At present, water resources evaluation is mostly performed by administrative units or water resources divisions to determine a quantity of regional water resources or a quantity of available water resources, and previous calculation of water-land-forage-livestock balance systems is mostly performed on the scale of administrative units (counties, towns, and villages) or water resources divisions, and mostly based on regional control. As a result, it is difficult to determine a quantity of available water resources in terms of field management of, e.g., family pasture units. Especially for family pastures that use groundwater as a water source, how to determine a proper quantity of irrigated artificial grasslands that may be developed and a quantity of livestock that may be raised for each household is particularly important for rational development and utilization of water resources and protection of ecological security of grasslands. In addition, in the past, the quantity of livestock raised was determined mostly based on grassland productivity (forage yield), but the forage yield often took only the quantity of forage into account, ignoring quality (nutritional value) differences among various types of forage, resulting in a waste of the forage or forage-livestock imbalance in actual practice. Therefore, how to provide a method and system for calculating water-land-forage-livestock balance in a family pasture by taking forage quality into account, which can determine a maximum supportable planting area of irrigated artificial grasslands and a maximum supportable quantity of livestock raised in a family pasture, is a technical problem that needs to be resolved urgently by a person skilled in the art. SUMMARY In view of the foregoing research status and existing problems, the present disclosure provides a method and system for calculating water-land-forage-livestock balance in a family pasture by taking forage quality into account, specifically as follows. The present disclosure first provides a method for calculating water-land-forage-livestock balance in a family pasture by taking forage quality into account, including the following steps: S1: constructing a family pasture available-groundwater-supply equation and a family pasture water demand quantity equation based on area parameters of various irrigated artificial grasslands and a quantity of livestock raised;S2: determining a water-land balance calculation equation based on an equality constraint condition between the family pasture available-groundwater-supply equation and the family pasture water demand quantity equation;S3: converting various grasslands into standard hay by using total digestible nutrients of forage of various grasslands, obtaining a yield of the standard hay of the various grasslands, and constructing an available-forage-quantity equation and a forage demand quantity equation based on the yield of the standard hay of the various grasslands, the area parameters of various irrigated artificial grasslands, and the quantity of livestock raised;S4: determining a forage-livestock balance calculation equation based on an equality constraint condition between the available-forage-quantity equation and the forage demand quantity equation; andS5: obtaining the area parameters of various irrigated artificial grasslands and the quantity of livestock raised by solving the simultaneous water-land balance calculation equation and forage-livestock balance calculation equation. Preferably, the family pasture available-groundwater-supply equation is: WS=R×β R=103⁢A×P×αp+∑iAi×mi×αiwhere R is family pasture groundwater recharge (m3); β is an exploitable coefficient; A is a family pasture land area (km2); P is rainfall (mm); αp is an infiltration recharge coefficient of rainfall; Ai is an area (hm2) of various grasslands, including irrigated artificial grasslands and natural grasslands; mi is an irrigation quota (m3/hm2) for various grasslands, and the natural grasslands are not irrigated, and have a quota of 0; and αi is an irrigation infiltration recharge coefficient; andthe family pasture water demand quantity equation is: WR=R×mr+Ai+mi+L×ml where WR is a water demand quantity (m3); R is a quantity of people in the family pasture; mr is a per capita drinking water quota (m3/person); L is a to-be-determined quantity of livestock raised (in unit of sheep); and ml is a drinking water quota for livestock (m3