Transcription

1

2

3 Wheat Health Management Cook and Veseth Crop rotation is probably the single most critical factor affecting the health and productivity of a future wheat crop.

4 Wheat Health Management Cook and Veseth Crop rotation allows time for natural enemies to destroy the pathogens of one crop while unrelated crops are grown.

5 Wheat Health Management Cook and Veseth Choose a sustainable economic approach that optimizes productivity while taking maximum advantage of, or at least not upsetting nature s own contributions to the health of the crop

6 IMPORTANT FACTORS SHORT-TERM STUDIES ARE NOT ACCURATE IN EVALUATING TREATMENTS SUCH AS TILLAGE OR ROTATIONS WHICH HAVE LONG-TERM IMPACTS.

7 IMPORTANT FACTORS ONE OF THE MOST IMPORTANT THINGS THAT CAN BE DONE TO IMPROVE THE PROFITABILITY ASSOCIATED WITH WHEAT PRODUCTION IS TO BETTER IDENTIFY MANAGEMENT PRACTICES NEEDED WITH ROTATIONAL CROPS.

8 Ten Points 1. Reduced and no-till system favor the inclusion of alternative crops. Tilled systems may not. 2. A two season interval between growing a given crop or crop type is preferred. Some broadleaf crops require more time.

9 Ten Points 3. Chemical fallow is not as effective at breaking weed, disease, and insect cycles as are black fallow, green fallow, or production of a properly chosen crop. 4. Rotations should be sequenced to make it easy to prevent volunteer plants from the previous crop from becoming a weed problem.

10 Ten Points 5. Producers with livestock enterprises find it less difficult to introduce diversity into rotations. 6 Use of forage or flexible forage/grain crops and green fallow enhance the ability to tailor rotational intensity.

11 Ten Points 7. Crops destined for direct human food use pose the highest risk and offer the highest potential returns. 8. The desire to increase diversity and intensity needs to be balanced with profitability.

12 Ten Points 9. Soil moisture storage is affected by soil characteristics, surface residue amounts, intercrop period, snow catch ability of stubble, rooting depth characteristics, precipitation patterns, and other factors.

13 Ten Points 10. Seedbed conditions at the desired seeding time can be controlled through use of crops with differing characteristics in regard to residue color, level, distribution, and architecture.

14 SEQUENCE IS ONLY ONE COMPONENT OF A ROTATION

15 Crop Rotations Proper Intensity Adequate Diversity Stable/Sustainable Profitability

16 PROPER INTENSITY Native vegetation is the best indicator of the range of intensities which are appropriate for a location.

17

18

19

20

21 PROPER INTENSITY Most of the plant growth problems blamed on no-till are the result of inadequate diversity or improper intensity.

22 PROPER INTENSITY Put water saved by no-till to work More high water-use crops and Cover Crops or Double Crops Proper intensity reduces risk Plant growth, nutrients, etc.

23 COVER and FORAGE CROPS Cover and forage crops provide the opportunity to increase both intensity and diversity in situations where production of a grain crop would not be possible, would be unprofitable, or would be excessively risky.

24 COVER CROPS In humid environments (tall-grass prairie or wetter) the goal should be to have something growing at all times. In areas with a limited growing season this will require the use of cover crops and/or forage double crops.

25 COVER CROPS In subhumid, semiarid, and arid environments cover crops can be utilized to increase organic matter and biological activity.

26

27 WEB SOIL SURVEY

28

29

30 Scotts Bluff Wheat to Corn Normal

31 Scotts Bluff Wheat to Corn /2 Normal

32 Scotts Bluff Wheat to Corn ½ Normal

33 Scotts Bluff WW-Fallow Normal

34 Scotts Bluff Pea to WW Seed 3.63 Normal

35 Scotts Bluff Pea to WW Harv Normal

36 COVER CROPS If you get stranded in a rain on the back 40, do you drive home across the tilled field or the pasture?

37 OPPORTUNITY COSTS If portions of a rotation DO NOT FAIL during an extraordinarily dry period, intensity is not correct.

38 OPPORTUNITY COSTS These rotations have not taken advantage of normal years and will fail in wet years.

39 OPPORTUNITY COSTS Winter Wheat-Fallow systems fail most years because something could have been grown in the fallow year.

40 ADEQUATE DIVERSITY Weeds and diseases are nature s way of adding diversity to a system which lacks diversity.

41 ADEQUATE DIVERSITY Nature s efforts to add diversity can be countered by adding beneficial diversity to the system.

42 ADEQUATE DIVERSITY AT LEAST THREE CROP TYPES. LONG INTERVALS OF 2 TO 4 YEARS ARE NEEDED TO BREAK SOME DISEASE AND WEED CYCLES.

43 Impact of Rotation & Low Disturbance On Weed Populations Weed of Interest: Downy Brome Number of Weeds Previous: 10 Number of Seeds Per Weed:100

44 Rotation Interval Vs. Weeds 1.0E+07 Weeds In Millions 8.0E E E E E E Years 1 Year Out 2 Years Out 2 In - 2 Out

45 Rotation Interval Vs. Weeds 1.0E+07 Weeds In Millions 8.0E E E E E E Continuous 2 In - 1 Out 2 In - 2 Out 2 In - 3 Out 2 In - 4 Out Years

46

47

48 Natural Control Benefit Cool-Season Weeds (such as Downy Brome) 2 Years of Warm-Season Crops (or Fallow) Reduce Number of Seeds > 95% (W-C-F) Same with Warm-Season Weeds Cool-Season Crops

49 Weed Life Cycle Green Foxtail Ap May June July Aug Sep Oct Foxtail ( E ) ** ( F ) ** Corn P W. Wheat

50 Weed Life Cycle Green Foxtail Ap May June July Aug Sep Oct Foxtail ( E ) ** ( F ) ** Corn P W. Wheat X X X

51 Does it Work? (Field Trial) Long-Term Rotation Study Cool and Warm Season Crops No-Till : Herbicides - Weed Control Weed Density After 12 Years (No Herbicides Number of Weeds / m 2 )

52 Rotation Design < - > Weeds Weeds (plts/m2) W-CP W-C-CP Pea-W-C-SB

53 Tillage - Rotation Design - Weeds Weed Density (No Herbicides Weeds / m 2 ) Weed Community - Similar Lowest Highest Tilled Site SW-W-C-Sun W-PM No-Till Site Pea-W-C-SB W-CP

54 Rotation Tillage Interaction (No Herbicides Weeds / m 2 ) Cool Warm Cool-Cool- Warm-Warm 2 vs 4 Contrast Tilled Site /5 No-Till Site /13

55 THE REAL COMPARISON Tillage and Poor Rotation gives 225 weeds/m2 No-till and GOOD Rotation 7 weeds/m2 That is 97% weed control

56 Tillage Seed Survival Green Foxtail Seed Placed at 3 Depths in Soil 0, 2, and 4 inches Measure Number of Live Seed Yearly

57 Tillage - Weed Seedling Emergence Weed Seed Shed: (once) No-Till Till (seed 1 3 inches deep) Count Seedlings Yearly, for 3 Years Several Species, Average of 4 Sites

58 Seedling Emergence - Tillage Seedlings (%) Till No-Till Seedlings Within a Year

59 Corn Pea WW Corn Seedlings (%) Seedlings Within a Year Till No-Till

60 Corn Pea Corn Seedlings (%) Seedlings Within a Year Till No-Till

61

62 DIVERSITY IN CROP TYPE Diversity in seeding date. Diversity in rooting pattern. Diversity in root architecture. Diversity in residue type. Diversity in insect pests.

63 DIVERSITY IN CROP TYPE Diversity in weed suppression. Diversity in micro organisms. Diversity in harvest date. Diversity in beneficials. Diversity in MORE.

64 SIMPLE ROTATIONS Winter Wheat-Corn-Fallow Winter Wheat-Corn-Canola S. Wheat-W. Wheat-Corn-Sunflower Winter Wheat-Corn-Pea Corn-Soybean

65 SIMPLE ROTATIONS Advantages Simple-limited number of crops to manage and market. Disadvantages Limited-all corn behind wheat or all winter wheat into spring wheat.

66 Rotations With Perennial Sequences WW-Pea-WW-Pea-WW-Pea-Alf-Alf- Alf-Alf Many other examples

67 Rotations with Perennial Sequences Advantages Simple-limited number of annual crops to manage and market. Excellent place to spread manure. Probably can produce more soil structure than annual crops (grass or grass mixtures) Biomass crops may hold potential

68 Rotations with Perennial Sequences Disadvantages Difficult to manage sufficient percentage of land in a perennial crop without grazing. (harvesting 40% of farm as forage is tough) (using less perennial minimizes impact) Marketing perennial crop is an issue.

69 COMPOUND ROTATIONS Combination of two or more simple rotations in sequence to create a longer more diverse system. EXAMPLE: S. Wheat-W. Wheat-Corn-SB-Corn-SB

70 COMPOUND ROTATIONS Advantages Limited number of crops to manage. Creates more than one sequence for some crop types. Disadvantages Limited ability to spread workload.

71 COMPLEX ROTATIONS Rotations where crops within the same crop type vary. EXAMPLE: Barley-W.Wheat-Corn-Sunflower-Millet- Pea

72 COMPLEX ROTATIONS Advantages Capable of creating a wide array of crop type x sequence combinations. Disadvantages Requires substantial crop management and marketing skill.

73 STACKED ROTATIONS Rotations where crops or crops within the same crop type are grown twice in succession followed by a long break. EXAMPLE: Wheat-Wheat-Corn-Corn-Soybean- Soybean

74 Stacked Rotation Concepts The goal is to allow sufficient time for pest pressure to decline to very low levels before sequencing the crop or crop type 2 times.

75 Stacked Rotation Concepts Attempt to keep pest populations diverse (confused). Diversity in sequences and intervals used. Mix of long and short residual herbicide programs. Reduces costs and minimizes the chance of resistance and biotype changes. Two year break between corn and wheat

76 STACKED ROTATIONS Advantages Reduces the risk of developing of biotype resistance. Can reduce cost of herbicide programs. Disadvantages Some crop sequences may not be ideal.

77 The goal is to be INCONSISTENT in both sequence and interval

78 Rotations Utilizing Both Stacked and Normal Sequences Canola-W.Wheat-Soybean-Corn-Corn S.Wheat-W.Wheat-Pea-Corn-Millet- Sunflower. WW-WW-WW-WW-Sorg-Sorg-Sorg- Sorg-SF-SF-SF

79 Dryland Rotations at DLRF W-W-Corn/Sorg-Corn-Broadleaf W.Wheat-W.Wheat-Broadleaf-Milo- Corn-Pea/Canola/Flax WW-Corn-Pea WW-Soybean-Corn/Milo-Pea

80 Irrigated Rotations at DLRF Continuous Corn (With CC) Corn-Soybean (With CC) Corn-Corn-Pinto-WW/CC-Soybean/Pinto Wheat-Wheat (CC)-Corn-Corn-Pinto/SB Soybean/Pinto

81 The Rotation Must Fit the Ecosystem and the Operator There is no set recipe or best rotation Individual fields may need differing treatment due to soils, location, proximity, history, landlord, ownership. Understanding the power or rotations is the key.

82 CATCH AND RELEASE NUTRIENTS

83 Irrigated Corn By Previous Crop Wheat-Wheat-C-C-SB-SB rotation 2009 Dakota Lakes Res. Farm Nitrogen rate impact on yields STN = 108 lbs/ac Yield goal = 220 bu/ac Rotation CC lentil, CVetch, turnip N rate 0 lb Yield Bu/ac N rate 36 Yield Bu/ac N rate 72 Yield Bu/ac N rate 108 Yield Bu/ac

84

85

86 Sb-Corn-Pea-WW Corn-Pea-WW

87 Rotation Impact on W.Wheat Dakota Lakes Research Farm Rotation Yield Precip* Corn-Pea-WW SB-Corn-Pea-WW Corn-Pea-WW Sb-Corn-Pea-WW Corn-Pea-WW SB-Corn-Pea-WW

88 2013 Yield Data Dakota Lakes Research Farm C SB rotation (Cover Crops historically increases soybean yield 7.3 bu/a on average vs no CC in this rotation). Yield 2013: Soybean with WW CC 62.9 bu/a. We would have expected around 55.6 bu/a without CC.

89 2013 Yield Data Dakota Lakes Research Farm C C SB Wheat - SB rotation 1 st year SB yield - NO cover crop = 76.3 bu/ac 2 nd SB yield Cover Crop = 81.2 bu/ac

90 2013 Yield Data Dakota Lakes Research Farm Cover crop increased SB yield (7.3 bu/ac), but more importantly crop diversity increased SB yield by 15.9 bu/ac. C SB rotation = 62.9 C C SB Wheat SB = 78.8 bu/ac

91 DIVERSITY IMPACT IF 5,000 ACRES CONTINUOUS CORN 203 bu/a CORN-SOYBEAN 217 bu/a C-C-SB-W-SB 235 Corn

92 DIVERSITY IMPACT IF 5,000 ACRES CONTINUOUS CORN 1,015,000 corn, 0 soybean, 0 wheat CORN-SOYBEAN 542,500 Corn, 157,250, 0 Wheat C-C-SB-W-SB 470,000 Corn, 157,600, 120,000 Wheat Lose 72,550 bushels of corn to gain 120,000 bushels of wheat, 350 bushels of soybeans, a chance to grow cover crops better, and better weed, disease, and insect control.

93 SPRING WHEAT YIELDS DORMANT VS MARCH SEEDING 1996 and AVERAGE DORMANT SEEDED 58.2 BU/A MARCH SEEDED 57.5 BU/A

94

95

96

97 ORGANIC MATTER MAKES A DIFFERENCE.

98