Soil moisture, nutrients, and weeds in no till
- 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
- 7. % NO-TILL FOR ALL CROPS, 2004 http://water.usgs.gov/nawqa/home_maps/images/no-till.png
- 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.
- 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)
- 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
- 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