Agro-meteorology questions.

In an Agro-ecological Zone where there is a Humid Period there is concurrently a Growing Period.

Although rainfall from a Standard Rain Gauge is conveniently measured in mm, it can still be measured in ml and reported in mm if the appropriate measuring jar is missing.

Determining moisture deficiency by appearance of the plant is both convenient and inexpensive.

A ‘weather  forecast’ is a statement of what the weather is going to be.

Invisible drought is easy to determine and mitigate through supplementary irrigation.

Explain how each of the following instruments is installed , how it collects data, how it is reset and give at least one application of such collected data.

1. Self-recording rain gauge
2. Gunn Bellani Radiometer
3. Compbell-Stokes Sunshine Recorder

Compute the water requirement of maize grown under irrigation in August using the Blaney-Criddle method. Data from a nearby weather station give average daily maximum and minimum temperatures as 30°C and 20°C, respectively . The crop coefficient for maize ranges between 0.75 and 0.85. August has an average of 310 h of sunshine out of an annual average of 3,660 sunshine hours. In August , the maize crop is in its peak vegetative/ reproductive phase.

Maize (Zea mays L.) Variety Ilonga COmposite White was grown for four months effective February 2011. Given the daily kc and Eto values for different crop growth stages in the table below, calculate this crop`s consumptive use and speculate on your results.

Compute evaporation using the data below, recorded from a Standard Evaporation Pan placed in an experimental plot.

Useful formulae