What sphinx of cement and aluminum bashed open their skulls and ate up their brains and imagination? Ashcans and unobtainable dollars!
In agriculture with heavy cash investments for modern inputs e. It may be desirable to express the efficiency of production with respect to very specific inputs. Stability is assessed in terms of the fluctuation of production about a long-term average Fig. The stability concept can be described in abstract terms by considering movements of a small ball on the landscape, as in Fig.
The position of the ball on the landscape represents Pesticide resistance essay the numerous aspects of agroecosystem organization and function, including production; point A represents the average condition of the agroecosystem including its production. Stability concerns movement of the ball about point A under the impact of disturbances that are not large enough to knock the ball all the way out of the valley.
Because stability derives from productivity, stability is multidimensional in exactly the same respects. A given agroecosystem can be relatively stable with regard to some measures of productivity and low with regard to others. Maize production for subsistence can be considered stable as long as yields and therefore food production are consistent, but the same crop may be considered unstable if grown for a market economy with fluctuating prices.
Figure 2 - The meaning of stability and sustainability in terms of the time course of production. Sustainability concerns whether a given level of productivity can be maintained over time Fig. In the abstract view of Fig.
As with stability, sustainability has a variety of measures associated with various measures of productivity.
Some measures of sustainability can be high while others are low for the same agroecosystem. The multidimensionality of sustainability derives in large part from the fact that it may be necessary to increase certain inputs with successive crops to maintain yields at the same level.
For example, if increasing fertilizer inputs are required to sustain production per hectare at a given level, the production per hectare may be sustainable even though production per unit cost is not. If weed problems require increasing labor inputs, production per hectare may be sustained while production per unit of labor is not.
Figure 3 - A ball and landscape model for visualizing stability and sustainability concepts. The horizontal axis of the diagram represents different states of ecosystem structure and function.
Figure 4 - Relationships of stability, resilience and sustainability. There is another important sense in which sustainability is multidimen-sional. On the one hand, a lack of sustainability may be due to internal processes ecological or social that cumulatively undermine agroecosystem productivity - e.
This is like movement of the ball from point A to point B in Fig. On the other hand, an agroecosystem can lack sustainability because it fails to produce satisfactorily under the impact of traumatic external disturbances such as unusually severe drought, the appearance of a pesticide-resistant pest biotype, an increase in the cost of inputs e.
Resilience is intermediate between stability and internal sustainability Fig. Like stability, resilience concerns the response of production to external disturbance; like sustainability, resilience concerns the maintenance of production. Stability concerns routine fluctuations in response to frequent and generally tolerable disturbances, while resilience deals with whether the agroecosystem can persist in the face of disturbances that are occasional but traumatic.
The same agroecosystem can be quite strong with regard to internal sustainability but low in resilience, or visa versa, because these two kinds of sustainability involve different processes. Multidimensionality of equitability and autonomy Equitability is most commonly measured in terms of the evenness of distribution of agricultural products or income.
A low coefficient of vari-ation for the distribution among households indicates a high degree of equitability. Equitability may be assessed with respect to the distribution of agricultural products or with respect to access to inputs such as land, capital or technical information.
Equitability of production and equitability in access to inputs are often closely linked, but not always. For example, fruit farmers may have equal landhqldings i.
Moreover, different measures of productivity can lead to different measures of equitability, in part because different kinds of agricultural products may be shared differently. For example, everyone in a community may have equal access to cropping fuelwood trees in ricefields, or the rats in ricefields where people eat ratsbut the rice production itself may be highly individualistic.
In addition, access to inputs may be more equal with respect to some measures of production than it is for others. If all households have similar quantities of land, their opportunities for subsistence food production may be correspondingly similar, and equitability for food production is high.
However, if they vary in their access to credit, technical information, or commercial markets, equitability for cash production may be low. Autonomy - which corresponds to less integration - is multidimensional because the magnitude of the flow of various materials, both within an agroecosystem and between the agroecosystem and the outside world, and the nature of the control of the flows, can be quite different for different materials in the same agroecosystem.
The degree of autonomy with regard to inputs may be different from the autonomy in marketing agricultural products. The degree of local control over agroecosystem flows may be different from their magnitudes.
Different agricultural activities of the same household may vary radically in their autonomy.Obviously this article is about Roundup and whether or not it’s safe to use around your home or farm.
But first I am asking for your support because I am about to be slammed to the ground, kicked, punched and pummeled with rocks just for writing this. And in a second I will tell you. Education and parenting articles offer expert tips and information on raising kids.
Read educational articles, parenting articles, & more. Silent Spring is an environmental science book by Rachel Carson.
The book was published on 27 September and it documented the adverse effects on the environment of the indiscriminate use of barnweddingvt.com accused the chemical industry of spreading disinformation and public officials of accepting industry claims .
Rachel Carson was an American biologist and writer whose book Silent Spring awakened the public to the dangers of pollution and its impact on the environment.
Because of her work, she is considered a pioneer in the modern environmental movement. In some circles, however, opposition to the concept of evolution has persisted to the present.
The argument from design has recently been revived by a number of academics with scientific credentials, who maintain that their version of the idea (unlike Paley’s) is soundly supported by both microbiology and mathematics.
by Megan L. Norris. Summary: As the prevalence of genetically modified organisms (GMOs) continues to rise, there has been an increasing public interest for information concerning the safety of these barnweddingvt.comns generally focus on how the GMO may affect the environment or how it may affect the consumer.
One specific concern is the possibility for GMOs to negatively affect human health.