Current Research Program

Transcription

1 Current Research Program

2 Current Projects 1. Improving Soil P Fertilization Recommendations (NRCS, Maui County) 2. Evaluating N Availability from Animal Manures in Hawaii Soils (NRCS) 3. Soil Organic Matter Management to Improve soil and Crop Quality (TSTAR) 4. Charcoal as a Soil Amendment 5. Evaluating Sensitive Measures of Soil Biological and Physical Properties

3 Improving Soil P Fertilization Recommendations Farm N ph P P Sufficiency Range ppm Ca K Mg ppm (190) (22) (4.6) (10) (95) (3.4) (48) (19) (86) (36) (7.5) (1.6) (2.1)

4 Improving Soil P Fertilization Recommendations Puukapu Farm 2 Kula Farm Fresh Yield (lb acre -1 ) Farm 7a FP Urea Urea+P Omaopio, 700 ppm Farm 7b FP Urea Omaopio 300 ppm FP Urea Urea+P FP Urea Urea+P

5 Improving Soil P Fertilization Recommendations Green Bean, Pulehu Bulb Onion, Omaopio Fresh Bean Weight (lb acre -1 ) Bulb Yield (lb acre -1 ) FP Urea Urea + P 0 Urea FP N+K

6 Improving Soil P Fertilization Recommendations 800 $772 FP Urea $ $ per acre 400 $ $197 $221 $151 0 Farm 2 Farm 7 Farm 5

7 Improving Soil P Fertilization Recommendations Fertilizer Blend Quantity P Added K Added Cost lb per acre $ per acre (Peters) 1, , , , , (A-1) Farmers can save considerable amounts of money if they don t need to add P

8 Improving Soil P Fertilization Recommendations Head cabbage yield response to increasing soil P in a Kikoni soil, Puukapu, Waimea. Critical level = 410 ppm Cabbage Fresh Wt (lb acre -1 ) Critical Level: 410 ppm Modified Truogg Extractable P (mg kg -1 )

9 Improving Soil P Fertilization Recommendations Romaine lettuce yield response to increasing soil P in a Waimea and Kula soil from experiments conducted at Lalamilo and Kula Experiment Stations Critical level = 600 ppm Relative Yield (FW) Lalamilo Experiment Kula Experiment Modified Truog Extractable P (mg kg -1)

10 Key Findings 1. Soils with soil test P > 700 ppm do not benefit from added P fertilizers 2. Current P critical levels used by ADSC are too low for vegetable crops

11 Ongoing and Future Experiments 1. Manoa lettuce, Waimanalo Exp. Stat. planted April Manoa lettuce, Poamoho Exp. Stat., planting date mid May, Broccoli, Kula Exp. Stat, June Molokai Exp. Stat., Summer 2007

12 Manure Experiments 1. Characterize N availability from three manures in an Oxisol, Mollisol, and 2 Andisols 2. Poamoho - 3 cropping cycles complete 3. Waimanalo - 2 cropping cycles complete 4. Mealani and Lalamilo - planting date mid-may

13 Poamoho, Oxisol Chicken Manure Poamoho Dairy Manure Swine Manure Fresh Ear Wt (lb acre -1 ) First Crop Second Crop Third Crop Fresh Ear Wt (lb acre -1 ) Waimanalo, Mollisol Chicken Manure Added N (lb acre -1 ) Dairy Manure Swine Manure First Crop Second Crop Added N (lb acre -1 )

14 Waimanalo Chicken Manure

15 N Release After 1 Cropping Cycle Treatment Poamoho Waimanalo N recovery Mean N recovery Mean % CM (17.2) 54.9(10.2) 25.9(41.1) 39.1(7.41) CM (17.8) 40.0(19.7) CM (21.6) 51.5(4.93) DM (34.0) 47.5(4.0) -11.8(28.2) 16.3(14.1) DM (8.1) 29.1(8.93) DM (14.7) 31.7(6.83) SM (44.6) 11.3(11.9) 6.51(12.6) 2.35(3.27) SM (9.3) -4.1(12.6) SM (5.6) 4.65(6.89)

16 Key Findings 1. Chicken and dairy manure produce similar yields in both soils % of N in chicken manure available for the first crop % of N in dairy manure available for the first crop 4. <10% of N in swine manure available to the first crop

17 Soil Organic Matter Management (TSTAR) Evaluate the effects of different soil organic matter inputs on the physical, chemical, and biological properties of soils that have been under long term conventional vegetable production. Determine whether increased values in soil biological and biochemical properties result in improved soil physical properties and increased crop yields. Determine the effects of organic inputs on the incidence of soilborne diseases. Increase farmer adoption of soil management practices that include organic matter inputs.

18 Study Sites Oahu Big Island O. Kaneshiro, Waianae E. Yamamoto, Lalamilo Maui J. Nozawa, Kahuku J. Shishido, Omaopio

19 Treatments: - Green manure (sunn hemp, sudex, annual rye - Fish/bone meal - Low N compost/manure (dairy manure, macnut compost, ecocompost) - Farmer practice (control) 3 Replications

20 Timeline Month Green Manure 1 Control Low N Compost Green Manure 2 High N Compost January Green Manure Green Manure April Compost Added Compost Added July Crop 1 September November Crop 2

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27 Charcoal as a Soil Amendment Source: energy.gov/biomass/pyrol ysis.html

28 Photo source: University of Bayreuth Terra Preta Soil Photo source: University of Bayreuth Typical Upland Amazonian Soil

29 Effect of Charcoal on Plant Growth Photo source: Charcoal Additions No Charcoal Additions

30 Materials and Methods Cultivated fertile, volcanic ash soil (Waimea Series) Flash Carbonized macadamia nutshell charcoal Lettuce 4 treatments, 3 replicates 0% (w/w) 5% (w/w) 10% (w/w) 20% (w/w)

31 Plant Effects Plant weight (grams/pot) Lettuce Shoot Biomass a a b c Plant Uptake (grams/pot) Lettuce Nitrogen Uptake a a b c 0 0% 5% 10% 20% % 5% 10% 20% Increasing rate of charcoal Increasing rate of charcoal

32 Corn Experiment 100 Corn Fresh Biomass Plant weight (grams/pot) a a a a 0 0% 5% 10% 20% 0% 5% 10% 20% Increasing rate of charcoal

33 Charcoal Effect in an Infertile Soil 70 Corn Fresh Biomass a b c c Plant weight (grams/pot) 0% 5% NPK + Lime 0 NPK + Lime 5% + NPK + Lime Control Control+5% Control+ NPK+lime Control+5%+NPK+lime

34 Volatile Matter (VM) content: a measure of the susceptibility of charcoal to further decompose and form carbon when heated Charcoal Behavior Upon Wetting Water Repellency Water Absorption 22.5% VM Content 6.3% VM Content

35 Corn Fresh Biomass Control 10% High VM 10% Low VM NPK+Lime 10% Low VM+NPK+Lime A A b c a Weight (grams/plant)

36 Conclusions High volatile matter content charcoal has a detrimental effect on plant growth BUT! Low volatile matter charcoal may have a beneficial effect on plant growth, especially when combined with fertilizer

37 Proposals in Review Accelerating cover crop technology adoption through field demonstrations using sunn hemp, oats, and buckwheat in rotational commercial production. (Conservation Innovation Grant) Anammox Activity and Nitrogen Dynamics in Sub-Tropical Watersheds (USDA-NRI)