This document discusses the benefits of no-till farming for soil moisture, nutrients, and weed control. It begins with an overview of the history of tillage and the dust bowl era that drove adoption of conservation tillage. No-till farming maintains soil moisture by leaving crop residue to reduce evaporation and erosion. It also builds soil organic matter and nutrients over time by keeping roots and residues in the soil. While no-till increases dependence on herbicides for weed control, precision weeders can reduce herbicide usage. Overall, no-till can help ensure more sustainable agricultural systems.

1. Soil moisture,
nutrients, and weeds –
we have the No-Till
situation
Olga Walsh, PhD
Cropping Systems Agronomist & Extension Specialist
Parma Research & Extension Center, Parma, ID

2. OUTLINE
• Tillage
• Dust bowl and soil erosion
• No-till:
• Adoption
• Soil moisture
• Nutrients (Carbon, Nitrogen)
• Weed control
***All processes are interconnected

3. TILLAGE
• Tillage = mechanical manipulation of soil for the
purpose of enhancing the growth of crops.
• Archaeologists discovered wooden plows which
were used in Egypt as early as 3000 B.C.
• Preparing an improved environment for seed
germination was the objective of soil tillage for
thousands of years.
Early wooden plow;
Egypt, 3000 BC
http://www.bae.uky.edu/lwells/BAE513/Lectures/Chap1new2.pdf; http://www.crustbuster.com/no-till-drills-and-planers

4. TO TILL OR NOT TO TILL?
• 1850-1900’s – transition from animal power to mechanical
• 1920’s – the Great DustBowl
• 1950’s – beginning of conservation tillage
• 1980’s – 50% of arable land in US is under conservation tillage
• Major drives: to reduce soil erosion and degradation and to reduce
energy inputs
http://www.kshs.org/p/forces-of-nature-part-3/16690; http://capita.wustl.edu/namaerosol/Dust%20Bowl%20map.htm

5. SOIL WIND EROSION
Wind erosion has
removed the surface soil
from this field, exposing
the less fertile subsoil
Eroding soil filling furrows;
Wheat plants blown out by a storm
http://www.weru.ksu.edu/new_weru/multimedia/storms/storms1.html

6. NO-TILL ACREAGE (2004)
http://www.washingtonpost.com/blogs/wonkblog/files/2013/11/spread-of-no-till.png

7. % NO-TILL FOR ALL CROPS, 2004
http://water.usgs.gov/nawqa/home_maps/images/no-till.png

8. NO-TILL ADOPTION

9. http://www.ringingcedarsofrussia.org/anastasia/ringing-cedars-settlements.html
NO-TILL:
• Apply herbicide
• Plant
• Apply herbicide
• Harvest
CONVENTIONAL TILL:
• Till with moldboard plow, burying up to 90% of residue
• Till with disk to smooth the ground
• Till with field cultivator to prepare the seedbed for
planting
• Till with harrows to smooth seedbed
• Plant
• Apply herbicides
• Till with row cultivator
• Harvest
CONVENTIONAL VS NO-TILL

10. NO-TILL CHARACTERISTICS
http://cropwatch.unl.edu/tillage/advdisadv; http://store.msuextension.org/publications/AgandNaturalResources/EB0182.pdf
• Excellent erosion control.
• Soil moisture conservation.
• Minimum fuel and labor costs.
costs.
• Builds soil structure and
health.
• Increased dependence on
herbicides.
• Slow soil warming on poorly
drained soils.
No-till systems influence:
• water infiltration
• soil moisture
• soil temperature
• nutrient distribution
• soil aeration
• microbial populations and activity.

11. TILL VS NO-TILL
http://semillanueva.org/saving-soils/

12. SOIL MOISTURE
• No-till farming can be considered as the most important tool to
prevent loss of soil moisture, especially during the drought
conditions (Barb Stewart, state agronomist with the USDA-
Natural Resources Conservation Service (NRCS) in Iowa)
• Soil tillage reduces soil moisture in several ways:
• Residue prevents soil crusting due to rain drop effect
• Reduces water infiltration by breaking up the large pores in the
soil structure, which act as large diameter pipelines for water to
soak into the soil profile
• Removes residue through tillage => soil erosion => eroded
particles of soil clog the smaller pores => prevent infiltration =>
cause soil runoff.

13. SOIL MOISTURE
Dry cloddy seedbeds severely restricted
soybean stand establishment in some
conventional tillage fields where no
substantial rain fell after planting (Columbia
City on June 21, 2012) (©2012 Purdue
Univ., T.J. Vyn) "
No-till soybean are more likely
to result in higher yields when
drought begins after good
early root system establishment,
even if relative no-till yields were
disappointing in years with a
very serious early drought

14. SM: CONVENTIONAL VS NO-TILL
http://soil5813.okstate.edu/Articles/NT%20in%20Argentina%20-%20A.Bianchini%20-%20V3.pdf

15. NO-TILL SM FACTS
• Every tillage pass can cause available plant moisture to drop .25 inch.
• Crop residue moderates soil temperatures, reducing soil moisture
evaporation, especially in the top two inches.
• Corn stalks can help trap snow, which can add up to 2 inches of soil
moisture after snow melt in the spring.
http://www.nrcs.usda.gov/wps/portal/nrcs/detail/ia/home/?cid=nrcs142p2_011847;
http://www.prairiefirenewspaper.com/files/201004-no-till-chloe.jpg

16. RESIDUE AND WATER
• Effect of stubble height on soil water
content change from fall to spring for a
4-foot depth in wheat-fallow at Mandan,
North Dakota (Kanwar, R.S., A. Kumar, and
D. Baker. 1998)

17. NUTRIENT LEACHING VS
RETENTION
http://semillanueva.org/wp-content/uploads/2013/09/Notill-infographic.png

18. ORGANIC CARBON
• Is a fraction of the soil solid components, crucial for soil
productivity
• Organic matter participates in the cycle of several nutrients, like
N and S, impacting in the soil chemical fertility
• Organic carbon enters the soil through the decomposition of
plant and animal residues, root exudates, living and dead
microorganisms, and soil biota.
• Indicator of soil quality

19. SOIL ORGANIC CARBON
http://www.cropscience.org.au/icsc2004/symposia/2/2/459_malikrk-5.gif
Organic carbon (%) in no-till and conventional tillage in 0-6 in layer
of soil, after 4 years of continuous no-till or continuous
conventional tillage wheat, India.

20. SOIL ORGANIC CARBON
• Soil organic matter
in the 0 to 8 inch soil depth,
6 to 10 years after the
conversion to no-till, Montana
• No-till systems maintain and
build soil organic matter
• The process requires
nitrogen!
http://store.msuextension.org/publications/AgandNaturalResources/EB0182.pdf

21. NITROGEN IN NO-TILL (N)
• To gain 1% SOM in the upper 6 inches of soil, it takes ~1,000 lb
N/a above crop need; N needs to be added over time, likely
decades.
• If no additional N added => lower crop yields due to inadequate N
=> less roots and stubble added to the soil => lower the amount of
SOM accumulation, reducing N mineralization => reduced available
N in future years
• Also: crop residue left on the surface affects soil temperature and
moisture content => affects N mineralization and efficiency of N
fertilizer use.
http://store.msuextension.org/publications/AgandNaturalResources/EB0182.pdf

22. NITROGEN ACCUMULATION

23. N MANAGEMENT IN NO-TILL
• More N (~40 lb N/a) is required due to lower N mineralization rates
and greater potential for nutrient stratification.
• N rates need to be slightly increased for several years, depending
on the field, to maximize yield and build SOM to save on N in the
long-term. More soil water increases N availability due to
increased N mineralization
• On-farm studies showed that long-term no-till (>6 years) should get
50 lb N/a credit, due to improved N availability and plant/microbe
balance
http://store.msuextension.org/publications/AgandNaturalResources/EB0182.pdf

24. PRECISION WEED CONTROL
Background:
 Cross and multiple herbicide-resistant weeds are evident in
Montana farm fields.
 Herbicide resistance management programs often use multiple
modes of action, which involve additional cost.
 WeedSeeker® sprayer could be a cost-effective technology for
precision weed control in chem-fallow.
 Operates on differential red and near infrared light absorption by a
green plant relative to bare ground or residue cover and activates
a solenoid switch above a spray nozzle.
 In collaboration with Prashant Jha, Weed Scientist, MSU

25. PRECISION WEED CONTROL
Objectives:
• Compare weed control efficacy
between WeedSeeker® and
conventional broadcast sprayer in
post-harvest wheat stubble.
• Determine the herbicide savings
using WeedSeeker® sprayer vs.
conventional broadcast sprayer.

26. PRECISION WEED CONTROL
Methods:
• Experimental Site: Southern Agricultural Research Center,
Huntley, MT; Year: 2013
• Target broadleaf weeds: Kochia, prickly lettuce
• Time of Application: Post-harvest wheat (15-30 cm-weed height)
• Sprayer: 5 foot, ATV-mounted, spray boom fitted with five
WeedSeeker® sprayer units equipped with flat-fan nozzles
spaced 12 in apart, to deliver 20 gal per ac

27. PRECISION WEED CONTROL
• Saved between 45 and 62 % in cost per ac
• WeedSeeker® technology is economically feasible to use high
rates of an herbicide or herbicide tank-mixtures.
• Cost-effective control of weed escapes and herbicide-resistant
weeds in chem-fallow/post-harvest wheat stubble.
• Greater environmental sustainability (less pesticide use per ac) at
the whole farm level.

28. THE FULL PICTURE - BALANCE

29. ARGENTINA NO-TILL SUCCESS
- 96% less soil erosion.
- 66% less fuel use.
- Maintenance or improvement of the organic matter.
- Higher water use efficiency.
- Increase in soil fertility.
- Lower production costs.
- Higher production stability and higher yield potential.

30. NO-TILL, PART OF SUSTAINABLE AG

31. THANK YOU!
Olga Walsh
Cropping Systems Agronomist and Extension
Specialist
Parma Research & Extension Center
owalsh@uidaho.edu
(208)722-6701
ID Crops & Soils blog: www.idcrops.blogspot.com
Twitter: @IDCrops