Answer:
A. Overtillage can increase the rate of humus decomposition
Explanation:
We refer to humus as any material of an organic nature that undergoes soil degradation. Humus is very important for agriculture because it has high nutrient levels that it provides to all crops. This causes more crop productivity, increases the producer's profit and increases the number of food available to the population.
Humus is a difficult to decompose material, but under favorable conditions it can decompose quite easily. Due to the presence of large amount of burnt organic matter in the soil, it is sometimes difficult to increase the humus content, so the exhaustion of this organic matter is caused by over tillage, especially in regions of tropical and sub-tropical climate, poorly managed. farmer protection and unprotected effects of erosion.
Answer:
65% of oxygen
Explanation:
To name a few: Oxygen-65%, Carbon-18%, Hydrogen-10%
Answer:Valves stop blood flowing backwards
Explanation: Valve are flags of tissue that control the direction of the blood in our heart.,it prevent the backwards flow of blood. valves regulate blood from flowing back into the atria.The right and left atrio-ventricular valves prevent blood from flowing backwards into atria. When the ventricle is full,the valve prevent backwards flow of blood.
