Major purposes of land preparation include all except:
Loosen soil to allow displacement where needed
The “ideal” soil is often considered to consist of ___% solid and ___% open or pore space. Of the pore space, ___% is small enough to hold water.
50, 50 50
A _________ reduces soil clod sizes, after disking, smooths the soil surface, does small-scale leveling.
Methods of soil conservation include:
Using grassed waterway, Strip cropping, Minimum tillage, Plowing on the contour
Soil degradation includes:
Salination, Compaction, Accerelated Erosion, & Loss of Organic Matter
The loss of organic matter with regular tillage may eventually lead to deterioration of soil structure and loss of water-holding capacity.
____________________ is an instrument that measures the soil moisture tension.
_____________ irrigation is a greenhouse irrigation system consisting of small tubes (like an IV tube) that supply water directly to each pot.
_____________ irrigation is an outdoor surface irrigation system used for row crops.
____________ is the use of agronomic or horticultural practices that favor plant development and minimize pest or pathogen activity.
Which of the following weed control methods are considered 'organic'?
Mechanical cultivation, Burning, Hay mulch
___________ is defined as suboptimal plant growth brought about by a continuous irritant such as a ________ or via chronic exposure to less that ideal growing conditions. In contrast injury is the loss of plant vigor from an instantanous event, i. e. a lightning strike.
Fungi cause __________ plant diseases than all of the other organisms combined. Fungi cna be beneficial by participating in the _________ _________ decaying organic matter, converting it to plant nutrients.
_________ involves the use of crop row spacing, crop rotation, flooding, mechanical cultivation, fire and mulches to enhance the crops ability to compete with weeds.
Cultural Weed Control
Plant __________ require a wound in order to enter the plant cells. Once inside they can move freely from cell to cell via the __________.
In an ecosystem with a complete vegetation cover (canopy), competition among plants will most likely be for:
Recycling in ecosystems is mainly carried out by
Saprophytes and detritivores
Alexander von Humboldt was the first to notice that:
Similar vegetation grew in areas with similar climate around the globe.
Convergent global air currents at 60 degrees latitude and divergent global air currents at 30 degrees latitude:
Bring rainfall and dry conditions, respectively
A collection of ecosystems with similar climate, soil, and plant composition are called:
An easy cropping practice that reduces topsoil losses is to____________—instead of up and down the hill.
Plowing on the contour
___________removes excess soil water, increasing air & oxygen concentration in the soil.
Repeated additions of ___________provide constant food and raw materials to soil organisms.
_________ are the most serious vertebrate pests, however deer, mice, gophers, squirrels, rabbits, nutriarats, beaver, racoons, and various birds may also become pests.
Those growing plants must have a firm understanding of weed science, __________/__________ and have to learn how to manage plant pests or otherwise minimize plant losses caused by importatnt plant pests.
Annual weeds are generally propagated by _________, while perennial weeds are regenerated in the same way and by ___________.
__________ is the use of pesticides to supress or inhibit pest/pathogen activities.
__________ of the crop plant to the pest may be the only cost effective pest control when growing large-acreage field crops like corn, soybeans, grains, and cotton.
Genetic Host Resistance
_________ is the use of beneficial or antagonistic organisms that kill or supress plant pests or pathogens.
The lands between _______ and ________ consists of ________.
Which of the following is correctly ordered from smallest scale to largest scale?
Individual species – communities – habitats – ecosystems – biomes
______ is the main influence on vegetation type.
The Hadley Cell is a circulation of rising air and precipitation over the ______.
Which of the following are known to support mutually beneficial associations?
Both Lichens and Rhizobium
_____ occurs when more than one organism draws on a resource that is in short supply.
The ___________ reduces labor by moving pipe across the field with a small gasoline engine.
Wheel-line irrigation system
The pH of acid soil can be increased by adding ___________.
To maintain or improve soil fertility, nutrients must be added in amounts __________those removed by crop harvest.
Equal to or greater than
____________ is defined as mechanical manipulation of soil to provide a favorable environment for crop growth.
Instead of plowing, disking & otherwise cultivating to remove old vegetation, ___________are used to kill the vegetation which is left in place.
Most insects have __________ economic impact on humans. Actually only _____% ever reach pest status.
A ___________ refers to a subpopulation of plants within a species differing only slightly from the general population.
Cultural priactices in pest management favor plant development, and minimize pest or pathogen activity. These practices include tillage practices, water management, __________, ___________, and sanitation.
________ turns arid lands to desert.
Crop production systems that are distinctly different from the locale’s preexisting biome are more difficult to sustain.
A mutually beneficial relationship between two organisms is called a ______.
______ exists when a resource is partitioned so that different portions are accessible to certain species.
After rainforest is cleared for agriculture, you may grow crops short term, because nutrients are rapidly ________.
Wetlands are __________ __________ _________ providing refuge for animals, and supplying moisture to plants and animals during dry times.