Chapter 6
Program AEZCCS05 LP Report Writer

Program AEZCCS05 reads the output from the AEZ land productivity assessment (program AEZCCS03) and the solution file LPSOL generated by the LP package to print out summary tables at a level of detail as indicated in the control file. It can be meaningful to call the program repeatedly with the same LP solution file but modified control parameters, e.g. to investigate the consequences of alternative soil conservation levels on the long term production potential.

6.1 Program Logic and Overview

Program AEZCCS05 resembles in many aspects the LP Matrix Generator AEZCCS04 discussed in the previous chapter. There are, however, important differences.

Both programs use the same scenario control input data, file CTRL$$$, (subroutine CTRLIN) where the user specifies the mode of operation and, optionally, a set of constraints. Aggregation indices, conversion weights and various technical coefficients at different levels of aggregation are read from a data set as specified on the scenario control file (subroutine L0ADT1). Then, the livestock systems definition tables are processed (subroutine LOADT2), and crop specific input requirements in table function format are read into memory (subroutine LOADTM). Several data buffers are cleared (subroutine CLRALL) which are to hold output summary statistics.

The program logic consists of two nested loops. The outer loop runs over land inventory records, the inner loop over crop combination records within a cell.

The main program loop starts with reading the cell information record from the productivity assessment file, an unformatted sequential file created by program AEZCCS03 (subroutine CELLIN). Then, basic accounting of cell extents takes place (subroutine ACCALC), the applicable population density is retrieved, and the crop combination records relating to the current cell are copied to a temporary working file (subroutine TBGET).

The temporary file is re-read and the crop combination records are processed (subroutine CMBIN). Each crop combination record is tested for non-zero activity level in the LP solution (subroutine LPSOL). If applicable, various land area counters are updated (subroutine ACCALC), and production from the currently considered crop combination is determined (subroutine QCCALC). The input requirements for production in terms of seeds, fertilizer, power and pesticides are derived from the technology matrix (subroutine INPUTS) and the respective weight in the objective function of the LP is calculated (function OBJFUN). The aggregate land use and production counters are updated (subroutine UPDCNT).

FIGURE 6.1
Information flow in program AEZCCS05

After having processed all the crop combination records available in the current land inventory cell, the program proceeds with reading the next cell information record continuing this operation cycle until all cells have been read and dealt with.

Finally, the program turns to the livestock activities (subroutine LVSIN). While processing all the crop combination information, the program also calculates and aggregates data on feed supply by livestock zone. This information is used to generate livestock zone and livestock system specific feed balances and production accounts (subroutine QLCALC).

If no errors or infeasibilities have been detected so far, the program ends with printing detailed information on land use, crop choice, production, yields, feed balances and input requirements, comparing supported population densities to estimated base year (1980 in the Kenya Case Study) and projected population densities in the year 2000 (subroutine LPTAB).

The print file contains information on land use by cell, crop tables showing land classes, yields and production under bad, average, and good climatic conditions, livestock production accounts, input requirement tables, and a district summary. The information flow in program AEZCCS05 is shown in Figure 6.1.

6.2 Input/Output File Sizes and Connections

^a) ‘V’ indicates a variable, district or country specific number of records.

^b) FS = formatted sequential, UR = unformatted random access, US = unformatted sequent.

^c) R = input, W = output.

^d) The size of the temporary working file SCR305 and the size of the LP solution file LPSOL largely depend on the complexity of the land inventory and the number of admissible crop combinations that have to be processed but are small compared to overall disk requirements of the AEZ-CCSpackage.

^e) ‘$$$’ in file names BIN.$$$ and OUT.$$S has to be replaced by the respective three digit district codes.

6.3 Subprogram Description

6.4 Program Control Data, File CTRL$$$

Each AEZCCS program is controlled by a short input data file which is usually read from standard input. Refer to section 5.4 in the previous chapter for a discussion of scenario control input data file CTRL$$$ which is used for both, to run LP Matrix Generator program AEZCCS04 and LP Report Writer program AEZCCS05.

6.5 Commodity Aggregation Data, File COMMDAT

Refer to section 5.5 of the previous chapter for a description of input file COMMDAT containing three record types, CF, CQ, and AG, which refer to three different levels of commodity aggregation, namely, crop list, agricultural production, and aggregate food commodity list, respectively. Each record type contains commodity name information and technical coefficients such as conversion weights and extraction coefficients. Examples of record formats taken from the Kenya Case Study can be found in Appendix D.

6.6 Livestock System Definition Data, File LVSDAT

This text file contains three record types, LZ, LS, and LQ, which refer to livestock zone definition records, livestock system definition, and livestock product definition, respectively. Refer to section 5.6 in the previous chapter for a description of the record formats and to Appendix D for examples.

6.7 Technology Matrix, File TECHMAT

Refer to section 5.7 in the previous chapter for a description of input file TECHMAT containing crop, land class, and technology specific input requirements in terms of seeds, fertilizer, power, and pesticides.

6.8 Scenario Summary Tables, File OUT$$$

Depending on the setting of control parameter IPRINT the LP Report Writer Program generates scenario summary tables at different levels of detail. Information can be obtained on cell-wise characteristics and use, summary tables in terms of the three commodity levels considered in the model, i.e. crop level, agricultural production level, aggregate final food consumption level, livestock system feed balance and production tables, and a district summary table. Examples 6.1 to 6.4 show selected results obtained for South Nyanza district in Kenya under a food maximizing strategy at intermediate level of inputs.

EXAMPLE 6.4
Crop production statistics. South Nyanza district, food maximizing strategy

References

FAO, 1976. A Framework for Land Evaluation, FAO Soils Bulletin 32, FAO, Rome. FAO, 1978–81. Report on the Agro-ecological Zones Project, Vols. 1–4, Methodology and Results for Africa, World Resources Report 48/1, FAO, Rome. FAO, 1984. Population Supporting Capacity Assessment Kenya, Mission Report, AGL,

FAO, Rome. FAO, 1987. World Agriculture: Toward 2000, FAO, Report No. C87/27, Rome. IBM. Mathematical Programming System - Extended (MSPX), and Generalized Upper Bounding (GUB), IBM Document No. SH20-0968-1, IBM Corporation, New York.

Murtagh, B.A. and Saunders, M.A. 1977. MINOS - A Large Scale Nonlinear Programing System, Technical Report SOL 77–9, Stanford University, California.