Irrigation game to grow corn

Ted Sammis

This is a description of a irrigation game that runs on an IBM computer with graphics. The corn crop is grown in UTAH and the amount of rain that occurs is determined by a random number generator. The game also selects soil type using the random number. If the available soil moisture is 15% then the soil type is clay. If the available soil moisture is 10% then the soil type is loam and if the available soil moisture is 5% then the soil type is sand. The corn crop requires irrigation to get full yield. You can irrigated the crop if you are sprinkler irrigating with any amount of water you desire when ever you desire but if you are furrow irrigation then the minimum amount of water you can apply is 3 inches to get the water to the end of the furrow. If you pay for information then you will know how much water is in the soil profile and should irrigate before the soil moisture reservoir is less than 50% depleted. Otherwise the plant will suffer moisture stress and yield will be reduced. If you over irrigate water will go to deep drainage and pollute the ground water, which in this game will cost you some money. If you irrigate a large amount in the beginning of the irrigation season, you will run out of irrigation water before the crop has matured.

This game can be acquired by selecting IRRGAME.EXE
Down load the program into a file area and then go to that file area and type irrgame.

Instruction for game to simulation corn growth

1. You will be asked for a random seed number. This number selects randomly a soil type from a sandy soil to a clay soil and the random amount of rainfall.

2. Put in your name

3. You will be asked to pay to find out what your soil type is.If you wish to know type "yes", you will be given the soil type by depth with the potential available water. If it is a sandy soil, we will have a low potential available water. The potential available water units are percentage (.05 inch of water per inch of soil for a sandy soil). Consequently, if you have 5 percent will have 0.6 inches of water for each foot of soil depth.

4. If you want to know the beginning soil water content type "yes".

5. You will have a picture presented of the soil water profile if the whole profile is filled with water, it will be at 5 percent for the full depth for sandy soil and if lower portion of profile is dry, it will show 000.

6. Soil water storage is the amount of water available throughout the growing season - if you want this information you should say "yes".

7. When you start the game, you will need to irrigate by typing the amount of water you wish to irrigate on the day that you wish to irrigate, such as 2 in. Do this by hitting the number 2 key when the day in the right hand corner of the page is the day you want to irrigate. Example if you want to irrigate 2 inches on day 95 then press the two key and the program will update on day 99 showing the increase water due to irrigation. The program updates every four days so you will not see the amount you put on until a few days have passed after you press the 2 in. or number 2 on your keyboard. If you press 2 in. it will say that 2 in. was irrigated on day 95. It will also tell you the day and the amount of rain that has occurred. You must irrigate whole numbers ie. 2 3 4 5.  If you use a muptiplier of 10000 then you can hold down the enter key to make the game progress in time. If you us 2000 then the game will stop ever 5 days and you need to make a decision and then hit enter.

8. Along the bottom of the graph you will find SO for Soil Water Content, AV for Available Water, IR for the amount of Irrigation Water, RA for the Amount of Rainwater, DR for the amount of Drainage Water, ET for the amount of water use by the crop as Evapotranspiration, and ETP for the amount of Potential water use by the crop. This have units of inches.

9. If the soil water (SO) becomes limiting less then 50% of AV the ET will be less, then the maximum ET and the yield will decrease. Consequently the object of the game is to irrigate when 50% of the water has been depleted. In the above game it is past time to irrigation SO is less than 50% of AV and you can see that ET is becoming less than ETp and the plant size is less than the potential plant size.

10.If you irrigate too much water, deep drainage will occur and you will be penalized for that. Consequently, sandy soil holds less water than clay soils and you should put lighter irrigation's on sandy soil and heavier irrigation's on clay soils.

11.The object of the game is to make money, decrease drainage, and not run out of irrigation water. If you irrigate all the water in the beginning of the growing season you will run out of water at the end of the growing season, the plants will go into stress and your yields will be reduced. If you put too much water on early, most of it will go into deep drainage and you will be charged for polluting the ground water.


ALT PRTSCN will capture the final screen output to past into your report.  

Students are usually better than teachers at playing this game. Good Luck.

If you have any questions please contact
Updated: Dec 18 1997
Copyright 1996 New Mexico State University
Department of Agronomy and Horticulture
Box 30001 / Dept.3Q / Las Cruces, N M 88003-8003
Telephone: (505)646-3405
FAX: (505)646-6041