Cropping Systems Flashcards Preview

Crop Management > Cropping Systems > Flashcards

Flashcards in Cropping Systems Deck (38):
1

Advantages of Crop Rotations vs monoculture crop (5)

  • risk spread across more than one commodity
  • pest life cycles can be interrupted improving pest control
  • yield of one or more of the rotational crops can increase compared to single crop systems
  • erosion may be less due to soil coverage
  • soil physical properties (infiltration, tilth) may improve

2

Disadvantages of Crop Rotations vs monoculture crop (5)

  • requires higher management, planning
  • may require different equipment
  • yield of one or more of the rotational crops may decrease compared to monoculture
  • timing management (seeding, fertilization, pest control) may be difficult
  • may be more soil compaction from implements

3

Crop rotation vs mono 

considerations

  • yields
  • soil physical, chemical, biological
  • insects, disease, nematodes, weeds
  • labor and equipment
  • production practices (fertilization, pest control, irrigation)
  • environmental issues
  • sustainability
  • economics

4

Fallow Cropping System

used to store soil water, control weeds, increase nutrient avail

  • soil water increased
    • using tillage, residue management
  • weeds reduced by
    • allowing weed germination, then control prior to seed set
  • Nutrient avail 
    • increases as organic matter decomposes 
    • less avail forms of nutrients converted to avail forms

5

Green Manure Crops / Cover Crops Role (4)

  • Grown to retain or add N in root zone for subsequent crop
  • protect soil surface from erosion
  • increase soil organic matter
  • increase infiltration / decrease runoff

 

Grown in rotation with major crop

 

6

Companion Crops Role

  • grown with major crop to completely cover surface of soil with harvestable crop
    • erosion control is possible 
    • major role is second harvestable crop on same acreage

7

Nurse Crops Role

  • grown to improve establishment of perennial crop (alfalfa, clover)

8

Describe how cropping sequence influences the following:

Residue Management

  • must consider next crop and whether or not residue will interfere with planting
  • Residue management includes
    • mulching
    • incorporation
    • burning
  • Short term effects
    • include impact of the residue on N avail 
    • pest occurrance
    • germination of following crop
  • Long term 
    • impacts of residues on
      • soil erosion
      • Soil organic matter
      • soil tilth and soil fertility

9

Describe how cropping sequence influences the following:

Moisture Availability

  • Rotational crop will use moisture, fallow conserves moisture
    • summer and fall fallow is practiced
  • Surface of soil kept free of weeds 
    • to reduce transpirational losses of water
  • Nutrient avail can improve

10

P  avail in fallow cropping systems

  • may be reduced due to fallow syndrome
    • loss of mycorrhizal activity on roots which assists plants in P uptake

11

Describe how cropping sequence influences the following:

Pest Management

  • impacted by cropping sequence from standpoints of control options and using the rotation as a control measure itself
  • pesticides used should not damage sunsequent crop
    • (pesticide residue carryover)
  • Pesticides can be used in one crop to control a pest that damages another crop in the sequence 
    • (if the latter crop is sensitive to direct application)
  • Crop rotation may serve to alter pest levels
    • rotational crop could be a poor host for a disease

12

Describe how cropping sequence influences the following:

Yield Potential

  • dependent on crop sequence
  • Changes in
    • pest pop'ns,
    • nutrient avail,
    • soil water
  • status for first crop may alter second crop

13

Describe how cropping sequence influences the following:

Herbicide Choice

  • depends on crop rotation
  • crops suscetible to damage preclude use of certain herbicides that might carryover

14

Describe how cropping sequence influences the following:

Fertility Management

  • takes rotation into consideration
  • crops that follow legumes may need less
    • N fertilization of one crop may be beneficial to the next crop

15

Compare clean till vs high surface residue management for the following:

Crop Rooting Patterns

 

  • Clean till
    • creates zones of increased soil bulk density (pans)
    • roots tend not to penetrate those zones
  • High Surface Residue
    • roots tend to concentrate more at soil surface due to increased fertility at the surface

16

Compare clean till vs high surface residue management for the following:

Seed Placement

  • Clean Till
    • soil zone containing adequete moisture, row width greater to allow tillage for weed control
  • HSR
    • soil zone containing adequete moisture using a no-till planter or drill 
      • row width narrower to shade weeds 
      • more seed per acre needed

17

Compare clean till vs high surface residue management for the following:

Pest Management / diseases

Clean Till

  • Tillage can be used as a control measure
  • Tillage may spread disease

HSR

  • Some soil and foliar diseases may be more prevalent
  • control is similar to clean till where rotations and varietal resistance to disease used

18

Compare clean till vs high surface residue management for the following:

Pest management Insects

Clean till

  • insecticides used
  • tillage can aid in control of overwintering habitat

HSR

  • insecticides needed

19

Compare clean till vs high surface residue management for the following:

Stand Estabilishment

Clean Till

  • Soil temp is critical if proper soil moisture for germination exists
  • crust can be disrupted by tillage

HSR

  • Must wait long enough for soil warming to give good germination and good stand
  • existing vegetation should be dead prior to seeding

20

Compare clean till vs high surface residue management for the following:

Fertilizer Placement

  • Clean till
    • usually broadcast
  • HSR
    • starter fertilizer placed below and to side of seed
    • fertilizer can be broadcasted or banded

21

Compare clean till vs high surface residue management for the following:

Water Management (precipitation, irrigation, drainage)

Clean Till

  • More runoff and less infiltration increasing need for irrigation

HSR

  • Increased infiltration and less runoff
  • less evaporation

22

Affect on Conversion of non-cropland to cropland:

Existing Vegetation

 

  • Affects cost of conversion in two ways
    • Vegetation may have value that can offset conversion costs
    • kinds / amounts of vegetation directly impact conversion costs
      • impact of conversion techniques 
        • tillage 
        • chemical vegetation control
        • erosion control

23

Affect on Conversion of non-cropland to cropland:

Pest Management

  • important part of the conversion process
  • after conversion pest managment programs can be affected by prior non-cropland type
    • weed seeds
    • viable root systems of weeds 
    • disease insect populations
  • from non cropland can impact crops to be grown

24

Affect on Conversion of non-cropland to cropland:

Nutrient Avail

  • soil often changes immediately after conversion followed by decrease in levels characteristic of cropping system
  • commonly related to kinds and amounts of soil organic matter

25

Affect on Conversion of non-cropland to cropland:

Yield Potential

  • of crop to be grown must be high enough to justify conversion costs

26

Affect on Conversion of non-cropland to cropland:

Erosion potential

  • can change and can be high during conversion process
  • erosions reduce value of land and threaten water in area

27

Affect on Conversion of non-cropland to cropland:

Soil Limiting Factors

  • soil depth, tilth, infiltration rate, drainage rate, pans, salinity, alkalinity

28

Affect on Conversion of non-cropland to cropland:

Water management

  • depend on
    • avail of irrigation water
    • water needs of crop
    • climate in area
    • infiltration / drainage rates

29

Affect on Conversion of non-cropland to cropland:

First Cropping Choice

  • will need to be economically viable and adapted to the conversion site in order to pay for coversion crops

30

Affect on Conversion of non-cropland to cropland:

Environmental Impacts

  • can go beyond erosion and water quality issues 

31

allelopathy

  • when one plant improves or impairs growth / development of another plant by release of chemicals

32

Autotoxicity

  • plant impairs growth of itself by release of chemical toxins
    • common in alfalfa where first seedlings are autotoxic to subsequent new growth

33

Cultivar or variety

  • plants are clearly different for others and whose offspring retain distinguishing characteristics of the parents

34

Hybrid vs open polinated varieties

  • Hybrid
    • offspring of two plants that differe genetically
      • crop crosses made to make plants superior
  • Open pollinated
    • pollination natural

35

impact on Hybrid Variety Selection

Maturity

  • refers to point in time when harvest can begin
  • selecting varieties of different maturity can be used to 
    • avoid environmental stresses
      • temp
      • drought
    • decrease harvest losses
      • shattering, wet/dry
    • Use harvesting equipment
    • allow double cropping

36

impact on Hybrid Variety Selection

Yield Potential

  • if yield is high and stress can be controlled, variety desirable 

37

impact on Hybrid Variety Selection

Adaptation to soil (pH, Salinity), climate (temp, drought, flooding) 

  • increase potential for good yield
  • varieties / hybrids that adapt can be developed

38

impact on Hybrid Variety Selection

Yield Stability

  • stability over years > high but inconsistent yields
    • better to plan for if yield potential known