I often come across a farmer who thinks his land might have a nitrogen deficiency, but then rules this out as he has fertilised with nitrogen at the usual rate and no leaching rain has fallen.
Invariably, though, a look at the soil reveals undecomposed crop residue. This is a ready food source for soil organisms, which then grow in number, in turn absorbing large quantities of nitrogen.
A hectare of soil can easily contain 2t of bacteria. The carbon:nitrogen (C:N) ratio of bacteria is 5:1. This means that 200kg of nitrogen is tied up in each ton of bacteria, the equivalent of 15 bags of LAN.
Simultaneously, fungi, actinomycetes, protozoa and other organisms that feed on both bacteria and plant residue increase, tying up even more nitrogen. In total, a hectare of soil can contain between 5t and 6t of living organisms.
Esta historia es de la edición June 15, 2018 de Farmer's Weekly.
Comience su prueba gratuita de Magzter GOLD de 7 días para acceder a miles de historias premium seleccionadas y a más de 9,000 revistas y periódicos.
Ya eres suscriptor ? Conectar
Esta historia es de la edición June 15, 2018 de Farmer's Weekly.
Comience su prueba gratuita de Magzter GOLD de 7 días para acceder a miles de historias premium seleccionadas y a más de 9,000 revistas y periódicos.
Ya eres suscriptor? Conectar
Review: the Toyota Hilux 2.8GD-6 DC 4×4 GR-Sport III
The third iteration of the Hilux GR-Sport has finally achieved a sense of presence and style befitting its raceinspired branding. But is this the ultimate modern Hilux? Car Magazine takes a closer look.
Why maize prices soar in Kenya and Malawi but not Tanzania
Namhla Landani, an economist at the Centre for Competition, Regulation and Economic Development, University of Johannesburg, and Arthur Khomotso Mahuma, economist and researcher at the Centre for Competition, Regulation and Economic Development, University of Johannesburg, analyse the issue.
Wet carcass syndrome: a scourge in SA sheep farming
Wet carcass syndrome continues to take a huge financial toll on South African sheep farmers. Octavia Avesca Spandiel spoke to two experts about the ongoing genetic research aimed at addressing this issue.
Pollination innovation
Bee-Tech Group is transforming South African agriculture with pollination technologies that boost crop yields and enhance sustainability. Founder Michiel Bruggeman spoke to Octavia Avesca Spandiel.
The valuable addition that makes this farm tick
Owning the value chain provides farmers with far more control over their produce. However, it requires a fine balance between production and ensuring there is a strong and steady market. Lindi Botha visited Rosemary Hill to find out how this essential oil producer leverages hospitality to make the farm viable.
The benefits of recirculating aquaculture systems
A powerful set of attributes has established recirculating aquaculture systems as a cornerstone of global temperate fish farming, writes Leslie Ter Morshuizen, owner of Aquaculture Solutions.
Minister has big plans for emerging and commercial farmers
DA leader and Minister of Agriculture John Steenhuisen spoke to Glenneis Kriel about his priorities for his department over the next five years, including an increased focus on biosecurity.
New study aims to make wheat more disease resistant
A recent international study explains how bread wheat has helped to transform the ancient world on its path to becoming the iconic crop that today helps sustain a global population of eight billion.
Conservation farming and biodiversity boost soil health and sustainability
A recent academic event focused on research into the links between soil biodiversity, soil health and sustainable agriculture
What has led to the unparalleled rice shortage in Japan?
Japan is facing a rice shortage amid concerns about a potential 'megaquake', several typhoons and an annual week-long holiday, which has led to an increase in panic buying.