Search results
Results from the WOW.Com Content Network
Thinning from below – this low thinning can be split into 4 Grades: A Grade is a very light thinning, that removes all overtopped trees Kraft crown class 4 and 5. B Grade is a very light thinning that removes overtopped trees and intermediates which are Kraft Crown class 4,5 and some 3s, C Grade and D Grade are a moderate and heavy thinning respectively removing anything that will not lead ...
Additionally crops such as sugar beet, spinach and onions are self-pollinating and do not require insects. [35] Nonetheless, an estimated 87.5% of the world's flowering plant species are animal-pollinated, [36] and 60% of crop plant species [37] use animal pollinators.
Agricultural expansion describes the growth of agricultural land (arable land, pastures, etc.) especially in the 20th and 21st centuries.. The agricultural expansion is often explained as a direct consequence of the global increase in food and energy requirements due to continuing population growth (both which in turn have been attributed to agricultural expansion itself [1] [2]), with an ...
Paulo Fridman/Corbis via Getty Images CC BY-ND Rising competition for many of the world’s important crops is sending increasing amounts toward uses other than directly feeding people ...
An example of ecological thinning research is the project in Victoria's Box-Ironbark forests, investigating various thinning and timber removal methods under an adaptive management or AEM framework. The primary objective is to generate (over time) a number of forest habitat values (i.e. tree hollows ) that are crucial for wildlife conservation .
Crop pests already account for approximately 1/6th of farm productivity losses. [195] Climate change will accelerate the prevalence of pests and diseases and increase the occurrence of highly impactful events. [195] The impacts of climate change on agricultural production in Africa will have serious implications for food security and livelihoods.
Boron is an essential micronutrient which means it is essential for plant growth and development, but is required in very small quantities. Although Boron requirements vary among crops, the optimum boron content of the leaves for most crops is 20-100 ppm. [8] Excess boron can result in boron toxicity and the toxicity level varies between plants ...
Since soil compaction can lead to a reduced crop growth and therefore to a reduced economic yield the use of fertilizer, especially nitrogen and phosphorus, is increasing. This growing demand causes several problems. Phosphor occurs in marine deposits, magmatic deposits or in guano. Phosphor extracted from marine deposits contains cadmium and uran.