EROSION CONTROL TECHNIQUES AND WEATHER INFORMATION UTILIZATION
Erosion control techniques are fundamental for the protection of water quality. Soil stabilization and erosion control practices are needed and should be used in areas where soil is exposed and natural vegetation is inadequate. Bare ground should be covered, typically with grass seed and some form of matting or mulch. This will help prevent erosion and subsequent movement of sediment into streams, lakes and wetlands. Erosion control measures need to be implemented immediately following construction and every time an area is disturbed. Soil erosion can be controlled by adopting land management practices and also by changing the pattern of some human activities which accelerate soil erosion. Erosion control is as well refers to coping or cropping techniques used exclusively with a view to reducing runoff and erosion damage.
Erosion Control Techniques
Five main techniques that can help in controlling erosion are as follows: (i) Contour Farming (ii) Strip Cropping (iii) Terracing (iv) Gully Reclamation (v) Shelter Belts.
(i) Contour Farming: Contour farming may be defined as ploughing, seeding, cultivating and harvesting across the slope, rather than with it. This simply entails making sure that cropping techniques follow contour lines. Soil roughness (clods and small hollows) must be laid perpendicular to the slope, so that the eventual runoff sheet is slowed as much as possible. The method is effective only on gentle slopes: the P (or erosion control practices) factor will be 0.5 on slopes between 1 and 8%, 0.6 on 8 to 12% slopes, 0.8 on 17 to 20% slopes, and close to 1 on slopes steeper than 25%. In other words, the steeper the slope, the less soil roughness can hold back water. A variant consists of alternating crops in contour strips, thus combining the above effect with that of rotating crops with varying degrees of sensitivity to erosion.
(ii) Strip Cropping: On land with a decided slope, planting crops on contour strips will be an effective erosion determent. For effective control the width of the contour strip should vary inversely with the length of the slope. Strip cropping should be combined with crop rotation so that a strip planted to a soil depleting, erosion-facilitating corn crop one year will be sown to a soil enriching and protecting strip of legumes the next.
(iii) Terracing: The practice of terracing has been common in ancient China. The flat, step-like bench terraces are now not useful. The modern terrace is an embankment of earth constructed across a slope in such a way as to control water run-off and minimize erosion. To be effective, terrace must check water flow before it attains sufficient velocity to loosen and transport soil.
(iv) Gully Reclamation: Gullies are danger signals that indicate land is eroding rapidly and may become a wasteland. If a gully is small it may be ploughed in and then seeded to quick-growing crops like barley, maize, wheat in order to check erosion. In case of severe gullying, small check dams of manure and straw constructed at 5 metre intervals may be effective because silt will collect behind the dams and gradually fill in the channel. Earthen, stone and even concrete dams may be built at intervals along the gully. Once dams have been constructed and water run-off has been restrained, soil may be stabilized.
(v) Shelter Belts: These are the – green belts – of trees which help to break the force of strong winds and thus, prevent or cut to a minimum the blowing away of the loose top-soil. In areas where wind erosion is more, rows of trees may be helpful to check the flow of winds. Apart from this, these trees will also add colour to the landscape and help to control the desert spread. Soil blowing away can also be controlled if local shrubs and small trees are planted in a systematic way. Even useful trees can be planted and harvested after a regular interval of two to three years.
Other measures of soil conservation are:
– Expansion of vegetative cover and protective afforestation;
– controlled grazing;
– Flood control;
– Prohibition of shifting cultivation;
– Proper land utilization;
– Maintenance of soil fertility;
– Land reforms, reclamation of wasteland;
– Establishment of soil research institute and training of soil scientists;
– Effective agencies for soil management;
– Break up channels. A channel is a spot where running water cuts into the soil and forms a rut. By filling the channel with compost or manure, helps preventing further erosion;
– Build a check dam or dike to stabilize the soil or gully bottom and
– Reduce the flow of water into gullies.
WEATHER INFORMATION UTILIZATION
Increasing economic pressures to optimize farm enterprise inputs and environmental concerns related to the stewardship of our land, water, and air resources are motivating those involved in agricultural production to be more sensitive to the impact of weather and climate variability. Delivery of timely and high quality agricultural weather information has become an important function of many state extension services. Nigerian agriculture is heavily reliant on rainfed production even after realizing the full irrigation potential, more than half of the cultivated area will continue to remain rainfed. Rainfed agriculture will need to support about 60% human population, two third livestock population and contributing over 80% to the food grain production of the country. But it is risky, vulnerable, diverse, and complex and under invested. Appropriate climatic information enhances small holder farmer – s ability to mitigate the adverse effects of climate change. It is also argued that to avoid disastrous consequences, fundamental changes in agricultural operations should go hand in hand with changing climate. This is because, timely updated information of weather and climate scenarios helps farmers to adjust their farming plans in accordance with weather and climate patterns of the growing seasons.
Concept of Weather
Weather simply refers to day to day meteorological condition, especially temperature, cloudiness and rainfall affecting a specific place. The growth of crop and their development are primarily governed by environmental conditions of soil and weather. The qualitative and quantitative improvements in crop production are intimately related to the prevailing conditions. The weather elements include temperature, precipitation and sunshine which are influencing the crop growth and yield. Weather assume significance in nearly every phase of activity from selection of crop varieties, time of sowing, transplanting, scheduling of irrigation, time of fertiliser application, using pesticides, harvesting process and storage decided by weather. Adverse weather warning for the same would be useful to farmer for estimating the nature of the impending attacks based on the current conditions and past experiences. So, that they can take suitable and remedial action and reduces losses. Temperature is important weather variable influencing crop production directly and indirectly. According to World Meteorological Organization (WMO) over the ten years from 2001 to 2010, global temperatures have averaged 0.46 – C above the 1961-1990 average, and are the highest ever recorded for a 10-year period since the beginning of instrumental climate records. Source and channels of weather information:
Sources of Weather Information
In Nigeria agro meteorological information disseminated through different channels and sources by various ministries and organisations involved for betterment of farming community and agricultural production. The Nigerian Meteorological Organization (NIMET) established a network of observatories all over the country and forecasting the weather information. Besides this general interest farmer – s weather bulletins are also issued, indicating precipitation, temperature and humidity and other farm weather related information. This information is disseminated in different regional languages through radio, television and the internet. The Agricultural Development projects (ADPs), universities and research institutions in different states also maintain network of agro meteorological observatories across the country. The ADPs prepare weather calendars which helps farmers to plan agricultural operation so as to take advantages of the favourable weather and mitigating the effects of adverse weather.
Utilization of weather information
Many aspects of the weather are critical to the agriculture community. Farmers must monitor observations to aid in their farm operations as listed below:
– The forecast of the weather events helps for suitable planning of farm
– It helps in to undertake or withheld the sowing operation
– It helps in determining the start and end of farm operations.
– It also helps in to take measures to fight frost.
– It helps in transportation and storage of food grains.
– Helps in management of cultural operations like plugging harrowing hoeing etc.
– It helps in measures to protect livestock.
Weather Forecasting And Its Classification
Means any advance information about the probable weather in future, which is obtained by evaluating the present and past meteorological conditions of the atmosphere is called weather forecast.
Agricultural weather forecast:
Forecasting of weather elements viz sunshine hours, occurrence of dew, relative humidity, rainfall, temperature, winds etc. Which are important in agriculture and for farming operations is known as agricultural forecast.In agricultural weather forecasting the advance information of weather elements like distribution of rain fall, warming for heavy rain fall, temperature change important special hazardous weather like if thunderstorm hailstorm, show or frost, sky cover, winds, humidity, dew drought, evaporation rate etc is provided.
Classification of weather forecasting:
- Short range forecast (SRF):
It is based on synoptic situation prevailing at the time of forecasting and is valid up to 3 days or 72 hrs. and are issued twice a day.
- Medium range forecast (MRF):
Forecasting of meteorological elements over different agro climatic zones for periods ranging from3-10 days is known as medium range forecast.
- Long range forecast (LRF):
The forecast valid for more than 10 days (i.e. a month or a season is knows as long range forecast.