#nutrient cycles

The Downside of Baled Crop Residue

For many years I have seen producers bale their crop residue, specifically cornstalks and soybean stubble, after harvest. This practice has been driven somewhat by feedlot demand after the advent of distillers co-products from ethanol plants in the early 2000’s. Distillers co-products are high in protein and energy for livestock. Therefore,  there is a demand for cheap roughage sources like baled…

AS and A-level Biology Specification Specifications for first teaching in 2015

Nutrients are recycled within natural ecosystems, exemplified by the nitrogen cycle and the phosphorus cycle.

Microorganisms play a vital role in recycling chemical elements such as phosphorus and nitrogen.

 - The role of saprobionts in decomposition.

 - The role of mycorrhizae in facilitating the uptake of water and inorganic ions by plants.

 - The role of bacteria in the nitrogen cycle in sufficient detail to illustrate the processes of saprobiotic nutrition, ammonification, nitrification, nitrogen fixation and denitrification.

(The names of individual species of bacteria are not required). The use of natural and artificial fertilisers to replace the nitrates and

phosphates lost by harvesting plants and removing livestock.

The environmental issues arising from the use of fertilisers including leaching and eutrophication.

AS and A-level Biology Specification Specifications for first teaching in 2015 Opportunities for skills development

PS 1.1

Micro-organisms are saprobionts/saprophytes;

Secrete enzymes (onto dead tissue) / extracellular digestion;

Absorb products of digestion/smaller molecules/named relevant substance;

Respiration (by micro-organisms) produces carbon dioxide;

Carbon dioxide taken into leaves;

Through stomata.