Renovation of raspberry fields

Transcription

1 Renovation of raspberry fields Tom Forge, Elizabeth Kenney, Bernie Zebarth, Denise Neilsen Abbotsford aquifer workshop Abbotsford, May 2, 2012 Pacific Agri-Food Research Centre Agassiz, BC V0M 1A0

2 Renovation of raspberry fields Stand vigour and berry yields begin declining after 4 to 7 years Soil-borne pathogens Root lesion nematodes Phytophthora rubi Viruses (RBDV) Soil chemical properties, e.g. ph The process: Deep tillage Fumigated (fall) Manure often applied (spring)

3 Root-lesion nematode: Pratylenchus penetrans Pathogen of all fruit crops in region Widespread (~75% of RB fields) Persistent, chronic stresses Infested plants more prone to other stresses disease complexes Photo: Oregon State Univ.

4 Raspberry decline and replant disorders are part of a broader problem: Declining soil health and productivity Declining soil organic matter and soil biological activity Lower mineralization of nutrients Reduced CEC and buffering Reduced WHC Compaction/reduced structure (biogenic) Loss of soil biodiversity Increased prevalence of soilborne plant pathogens Monoculture x Clean tillage x 30 yrs = degraded soil

5 Sustainable alternatives to fumigation are needed Emerging restrictions on fumigation Buffer zones Detrimental to soil health Short term benefits vs long-term decline...that minimize impacts of root pathogens and enhance soil health Pathogen suppressive cover crops? Organic amendments? manures and composts

6 The challenge: To use manure-based amendments to manage root diseases/enhance soil health without increasing nitrate leaching ~330,000 tons poultry manure produced in FV in 2010 Regional recycling imperative Is composted manure an option? Need to clarify distinctions between compost and manure

7 Compost vs- manure: properties Organic Ammonium Nitrate 60 Reduced risk of fecal contamination C/N 15 to 25 minimal NH 4 -N & organic acids humic acids & thermophilic microflora little labile C less rapid stimulation of soil microbial biomass (immobilization) g N per kg material PMC BM LM more stable N release greater potential to increase soil C per unit PAN

8 Compost vs- manure: disease suppression Compost Suppression demonstrated for many fungal pathogens Mode of action: enhancement of antagonistic rhizosphere microbes; SIR Previous research limited to incorporation into potting media or seed beds Suppression of parasitic nematodes under field conditions? Manure Suppression demonstrated for some fungal pathogens and nematodes Mode of action: biofumigation Ammonia, VFA's, etc. Large doses required Previous research limited to annual crops; longer-term influences on soil health and suppression not considered

9 Renovation experiments How do fumigation, fall cover crop, manure and compost compare with respect to? 1. Pathogen suppression 2. Crop establishment 3. Potential for N leaching fall winter Treatments: 1. Control 2. Fumigation (Dazomet) 3. Fall barley cover crop 4. Low spring manure (100 kg PAN/ha) 5. High spring manure 6. High spring compost

10 Renovation experiment 1: setup - spring inch application ~57 Mg/ha manure (2700 kg N/ha) ~88 Mg/ha compost (1650 kg N/ha)

11 Pratylenchus population dynamics org. amends applied planted

12 Cane counts & cane diameters 2011 (end of second growing season) a b ab b c c

13 Soil Physical Properties Raspberry Renovation July Bulk Density gm/cc Treatments t1 control t2 fumigate t3 cover t4 low manure t5 high manure t6 compost See Kenney poster for more on physical properties

14 Soil chemical properties See E. Kenney poster for more

15 Similar quantities of material, different implications for nitrate leaching a a b planted Amend s applied c b c

16 What have we learned? If composted, manure can be used in the raspberry production system to improve soil conditions and crop health: Reduce pathogen populations Improve soil physical and chemical properties Improve early raspberry growth With reduced risk of nitrate leaching With reduced risk of fecal bacterial contamination Next steps Other composts Lower rates Application to beds Economics of composting/utilization

17 AAFC-SAGES AAFC-GAPS Raspberry Industry Development Council Washington Red Raspberry Commission Thanks! Chaim Kempler Brian Harding Mark Sweeney Tom Walters Carol Koch Shaobing Yu Naomi Hashimoto Nathalie Armstrong Ben Frey Dru Yates Melissa Iverson

18 Pre-leaching 2010 Effect of low crop vigour org. amends planted

19 Nitrate-N (kg N/ha) Soil nitrate: Second fall/winter kg NO3-N/ha a a ----b b ----c---- Oct. 1, 2010 Nov. 7, 2010 Control Fumigate Cover crop ManLow ManHigh Compost Similar quantities of material, different implications for nitrate leaching

20 Primocane biomass & P. penetrans, 2010 a b b c c bc

21 Renovation experiment 2 (2010) 7 treatments x 5 reps fumigate+compost treatment Canes removed & plowed Aug. 30 Rototilled & barley planted September 21 Fumigated Oct. 1, 65 g/m2 Soil sampled Oct. 1 (before fumigating)

22 Renovation experiment 2: P. penetrans population densities a z b b yb y x x y yc c c

23 Mt. Vernon study Surface application of manure and compost to established crops Clearbrook studies Can we measure benefits if surface applied at modest (N-based) rates soil health indicators and nutrient availability

24 Surface application at N-based rates Modest improvements in growth/yield but no clear differentiation between manure and compost Biodiversity & organic matter accumulation Compost > manure > fertilizer Mixed results re. Pratylenchus penetrans Variation in root biomass related to P. penetrans population densities CDMS may reduce soil NO 3 -N without affecting crop N reduced risk of leaching Enhanced soil food web/nutrient turnover compensates for smaller pools of mineral N? Need longer-term experiments consider P loading effects on N use efficiency