Use of weather apps in farming
summer cropping THE season in Zimbabwe normally starts around mid-November.
But with November having come to an end last week, farmers continue wondering when they are likely to receive meaningful rains that will signal the start of the cropping season.
This highlights the importance of weather forecasting in farming.
With modern technological advancements, several weather applications are now available on our cellphones to predict weather patterns.
Weather forecasting uses a place’s location and historical data to predict the rainfall, sunshine, temperature, humidity and air conditions.
Weather forecasting enables a farmer to plan their operations such as planting, fertiliser application, weeding, spraying and irrigation. The general rule with spraying chemicals like herbicides on crops is that they should be applied at least six hours before a downpour. If it rains within those six hours, then it is likely that the chemical will be washed away, and a repeat spray is recommended.
If it is too windy, then the chemicals are likely to be blown away.
While farmers can dry-plant crops like maize, it is risky to dry-plant crops like soyabean. This is because the oil in the seeds is likely to be drained into the soil while the rhizobium that is normally mixed with soyabean seed at planting will not survive the high temperatures likely to be experienced without effective rains.
Before the advent of weather apps, farmers used to rely on their intuition, as well as their past experiences and traditional beliefs, to predict the weather.
For example, our elders would say, if you experience a spring season with very few mazhanje, then that is likely to be a drought year.
They would also be able to predict when the rains will come by observing movements of the moon. If the moon was too high in the sky, then it was unlikely to rain.
While these traditional methods served our forefathers well, they have since been rendered inaccurate by the frequent and unpredictable changes to the weather patterns brought about by climate change.
Climate change has brought with it lots of floods, storms and frequent droughts. This year, weather experts had already predicted that we will experience the effects of El Niño, a phenomenon that is associated with below-normal rainfall.
However, farmers still expected the rainy season to start normally, before probably ending prematurely.
But, as it has turned out, the start of the rainy season has been delayed.
It is also puzzling that some parts of the country, like Bulawayo, which is traditionally dry, have received more decent rains to date compared to the northern areas, which are normally a reliable rainfall belt.
Weather forecasting can be divided into short-range (up to 72 hours), medium-range (three to four days) and longrange (15 to 45 days) categories.
An obvious question that lingers in the minds of most people centres on the accuracy of these apps.
A short-day forecast is likely to be accurate 80 percent to 90 percent of the time. However, the longer the range, the more likely it is that the predicted variables might
Weather apps
Variables that are normally given with weather forecasting include temperatures, relative humidity, wind speed and direction, cloud cover and precipitation.
There are several weather apps that one can download and use.
While most are free, there are a few for which one will need to make a small payment.
The most common weather apps include AccuWeather (free), Hurricane (free), Weather Underground (free), DarkSky (not free) and RadarScope (US$9,99).
Most of the free apps can also be upgraded at an additional cost.
AccuWeather provides a minute-by-minute precipitation update and is free to download.
Weather Underground is said to collect data from over 270 000 weather stations and is highly accurate.
DarkSky is known for its reliability. It is known for being one of the most accurate weather apps.
While most weather apps provide basic features, the upgraded ones will be able to provide extended forecasts, alerts and location tracking.
One of the most pertinent questions on most farmers’minds right now is whether they should plant now or wait for the rains to fall. Let us say, using the weather apps on your phone, the prediction is that it will only rain around the first week of December, should you, therefore, wait until then?
A farmer can dry-plant crops like maize in anticipation of future rains.
However, there are a few points that farmers should take note of.
Firstly, when dry-planting, make sure the soil is dry because the slightest moisture in the soil will cause the maize seed to rot and fail to germinate.
Maize that is planted at the correct depth in dry soil can sit in that soil for more than two weeks and still germinate when it receives enough rainfall.
So, the maize must be planted at the correct depth.
If you plant your maize too shallowly, it can be easily reached by light showers.
Maize planted at the correct depth cannot be reached by light showers and will continue to sit in the soil, waiting for effective rains.
Therefore, when dry-planting, make sure you plant your maize to a depth of approximately 7,5cm.
However, when planting into moist soil, that depth should be reduced to just 5cm.
Maize requires effective rains of not less than 25mm within 24 hours for it to germinate. If it is inadequate, but reaches the maize seed, the seed will start the germination process, but the moisture soon runs out and the seed will rot.
In addition, growers who farm on red/ black clay soils should always try to prepare their lands and plant before the rains. The reason is: Once it rains, they must wait for many days to be able to access the land again.
The start of the season has already been delayed and if one must wait for days just to be able to gain access to his/her land, that means losing more precious days for the crop to grow. In a drought season, one cannot afford to do that; every day counts. Alternatively, farmers who wish to wait for the rains before planting should closely follow weather forecasts on weather apps.
They should only plant if the weather forecasts effective rainfall within a day or two, as it is important that once the germination process starts, there is sufficient moisture in the soil to see the crop germinate.