There are approximately 1,4 billion km3 of water on earth. It is found in different environments and in three distinct phases.
Next time you drink a glass of ice water, consider that you are experiencing water in all three its phases. The solid ice cools the liquid in your glass, and the air you breathe is full of water vapour. This is possible because it can naturally exist in all three its phases in the temperature and pressure ranges that are common on earth.
Ice in the polar regions freezes and thaws with the seasons and plays a crucial role in regulating the earth’s climate. Water also has a remarkable ability to absorb and retain heat. The sun delivers a tremendous amount of energy to the earth every day and the tropical oceans absorb much of that energy. In addition, a lot of it goes to creating water vapour, which is the source of all rain and snow. The 13 trillion tons of water in the atmosphere is responsible for absorbing approximately 70% of all atmospheric radiation from the sun.
Water in different environments
Phase change depends on temperature and pressure. During each phase change a specific amount of latent heat is either absorbed or released without the sensible temperature changing. These different processes contribute to cooling and warming the air in the troposphere (Figure 1).
The oceans contain approximately 97,25% of the total volume of water on earth and cover 70,8% of the planet’s surface. The water in the oceans plays a key role in regulating temperatures across the globe.
Water on land consists of the following:
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Shongololo Boer Goat Stud: Only The Best Will Do
South African Boer goats have proven popular worldwide for their ability to improve indigenous goat breeds. In addition, Covid-19 restrictions necessitated the establishment of electronic auctions, making it easier for foreigners to acquire outstanding genetic material exported by agents via established channels.
Feed Additives: A Veterinary Perspective
In an already volatile environment, dairy profit margins vary as milk prices and feed costs shift annually. Feed costs represent the largest input cost (an estimated 35 to 70% of the variable cost) in the production of milk. As a group of feed ingredients, feed additives can cause a desired physiological response in a non-nutrient way, such as pH shift, growth or metabolic modifier, and will usually be cost-beneficial.
Guard Against Lumpy Skin Disease
Most parts of the country received good rains during the rain season and producers are generally very optimistic. Wet seasons unfortunately come with their own set of challenges and veterinarians have cautioned livestock producers to keep an eye out for elevated biting insect loads, which may lead to conditions such as lumpy skin disease (LSD).
Climate-Related Hazards: How Smallholders Can Mitigate Its Consequences
Rainfed crop production remains the main source of food security and livelihoods for rural communities in South Africa but presents the challenge of climate variability due to its high dependence on weather variables such as rainfall and temperature.
Tips for a successful AI programme
The success of an artificial insemination (AI) programme depends on several factors that are largely within the control of the producer. It is interesting that those producers who take a hands-on approach to their cattle and inspect them regularly are also the ones who achieve the greatest success. Before his passing, Stockfarm spoke to Koot Louw, a well-known reproduction technologist from Brandfort in the Free State, about his insights into and advice regarding the AI process.
Pay Attention To Orf In Your Flocks
Some of our readers may have treated or heard of sheep or goats that have been infected with orf (vuilbek).
Sanele Mbele: Where Passion And Skill Meet
Passion for farming runs strong in the Mbele family’s veins. Sanele Mbele, from the farm Rietspruit in the De Jagersdrift area near Dundee, has inherited this passion in huge dollops.
Land Reform: Case Studies In Kwazulu-Natal
Land reform in South Africa is complex. Land reform solutions are equally complex and within partnership and development models, this is no different – but there is hope. KwaZulu-Natal has several types of partnership models and the wide variation in farming systems, as well as their different needs, set each model up for different strengths and weaknesses.
Brahman Breeders In Limpopo Have A Winning Plan
Several breeders from the Bosveld Brahman Club in Limpopo are applying genetic excellence and genotypic correctness to stimulate the demand for their bulls. At several of the last auctions, the minimum standard of bulls was raised to achieve this goal.
A Brahman Dream Comes True
For as long as he can remember, JP Mlangeni wanted to be a farmer. It might have taken a few years, from being a teacher and later a businessman, but his dream finally took shape and today he runs a fully-fledged breeding and commercial Brahman farming enterprise in Mpumalanga.
