Tillage and Cropping Systems Flashcards
What are the advantages of plowing?
It produces a friable seedbed well suited for planting small-seeded vegetables that need good soil contact to germinate, destroys existing weeds, buries the remains of the previous crop, aids disease control by burying contaminated residue, warms faster in the early season compared to soil covered with residue, which leads to earlier maturity.
What are the disadvantages of plowing?
The bare soil produced is prone to erosion, the heavy equipment used to plow and till compacts soil, uses energy and requires labor, and weed seeds are brought to the surface.
What is conventional tillage?
When <15% of previous crop residue remains on the soil surface following establishment. It’s “full-width” tillage because 100% of the topsoil is moved and mixed so that the majority of crop residue is incorporated into the soil..
What is the “stale bed” technique?
The seedbed is prepared several weeks before the intended planting date so weed seeds germinate before the crop is planted, and then herbicides or shallow cultivation are used to kill the first flush of weeds. The stale bed technique is sometimes difficult to employ because a wet early season may prevent soil preparation in advance of planting.
What is “conservation tillage”?
Any method of soil cultvation that minimizes soil disturbance and leaves the previous year’s crop residue in fields before and after planting the next crop. To be considered conservation tillage at least 30% of the soil surface must be covered with residue after planting the next crop. Crop residues reduce soil erosion, conserve moisture, inhibit weed growth and build soil organic matter.
What is a “no till” system?
Where the soil is left undisturbed from the time the previous crop is harvested until the new crop is planted, nutrients are precision placed in the soil rather than broadcast, and transplanting or seeding is accomplished in a narrow seedbed or slot. Weed control is accomplished through herbicides, by hand, or by mowing.
What is “strip tilling?”
Planting crops in a narrow tilled space with chisels or tillers cleared of residue with row sweepers while the rest of the field is left untilled.
What is “ridge tilling?”
Planting row crops on permanent ridges about 10–15 cm (4–6 in) high. The previous crop’s residue is cleared from ridge-tops into adjacent row middle furrows.
What is “mulch tilling?”
Tilling that leaves at least one-third of the soil surface covered with crop residue. Weed control is accomplished by hand, herbicides, and/or cultivation.
Why is conservation tillage less popular for vegetable cultivation?
Because of the extensive use of plastic mulch, which requires a smooth seedbed free of residue and because successful stand establishment of direct-seeded vegetables requires small soil aggregates to ensure good seed-to-soil contact.
What are adjustments that can be made to overcome some of the disadvantages of conservation tillage for vegetables?
Adjustments for planting in cooler soils resulting from conservation tillage include shallow planting (2.5 cm, 1 in or less), good seed–soil contact, slow planting (pull the planter at 8 km/h, 5 mph or less), use of high-quality seed, and use of pelleted seed to ensure good soil contact.
What techniques can be employed to decrease root rot disease?
Planting when the field is not excessively wet, using ridge-till or raised beds to promote drainage, install tile drainage systems in fields, treating seeds with fungicide or biological controls that reduce disease, and using disease-resistant cultivars if possible.
What are strategies to prevent or reduce erosion in a field?
Never leaving a field uncovered, such as with a cover crop or a residue of a cover crop; using waterways, which are natural or constructed outlets for water that are protected from erosion by grass or other perennial cover that holds soil, contour cropping which tills and orients crop rows along lines of consistent elevation on sloped land in order to conserve rainwater and to reduce soil losses from surface erosion, strip-cropping, which alternates contour strips of sod and row crops, and terraces, which are channels or ridges built across slopes to catch runoff water and shorten the length of a slope.
Why is the C:N ratio of a green manure important?
Because t will impact the rate of decomposition, the nutrient content of the soil and N availability for the cash crop. The C:N ratio should be less than 30:1 to prevent the bacteria from decomposing the green manure crop after it is incorporated into the soil, which would deplete existing soil N.
When is a C:N ratio above 30 valuable?
When the cover crop is used to provide mulch for a vegetable crop planted into residue in a no or minimum tillage production system.
