Phosphate h Fertilizer Needs in Quebec

Transcription

1 Les Journées Vertes Annual Meeting, La Coop fédérée Hilton Quebec City, QC 27 January 21 Phosphate h Fertilizer Needs in Quebec Tom Bruulsema, PhD, CCA Director, Northeast Region, North America Program IPNI Mission to develop and promote scientific information about the responsible management of plant nutrition for the benefit of the human family. Outline 1. Functions of P in plants 2. P behaviour in soil and soil test interpretation 3. P in starter fertilizers 4. Cropland P balance and soil test status 5. Regulation, environment and 4R Nutrient Stewardship 1

2 Phosphate in plants Nucleic acids DNA, RNA, etc. P Energy transformations triose, pentose, hexose sugars Phospholipids in cell membranes Storage forms phytate and inorganic P Signalling compounds inositol triphosphate P A phosphate molecule links each & every base in the rungs of the ladder in the DNA molecule P Photosynthesis & Respiration Carrier of energy compounds (sugars) Cytoplasm Chloroplast Marschner, Mineral Nutrition of Higher Plants. 2

3 Cell Membranes (phospholipids) P Some Roles Phosphorus Plays in Plant Growth Photosynthesis and respiration Energy storage and transfer Cell division and enlargement Root proliferation Transfer of hereditary traits Hastens maturity and reduces grain moisture at harvest P Helped the Corn on the Right to Mature Faster 3

4 Phosphorus Lowers Grain Moisture at Harvest P 2 O 5 rate, Yield, Moisture in kg/ha t/ha grain, % Low P soil Illinois IPNI Soil Fertility Manual Late Planting of Full Season Corn Increased Response to Starter in Wisconsin Source: Bundy, 21 P Deficiency in Corn Seedlings 4

5 t/ha Early season P nutrition is critical Early season P deficiency limits yield potential Critical period: first 5 to 6 weeks P has major impacts on tillering and rooting Wheat absorbs only 15% of total P uptake in first two weeks of growth Small amount but critical for optimum yield Reserves can support later growth Photo courtesy of the USDA NRCS Later season P stress has much lower impact on crop production 5

6 Wheat tillers Fourth leaf L4 Fifth leaf L5 Third leaf L3 Wheat produces two kinds of stems: Main stem Tillers Second tiller T2 Second leaf L2 Coleoptile tiller T First leaf L1 First tiller T1 Nodal roots Seed Seminal roots Wheat Plant Goos and Johnson, 1996; Klepper et al., 1982 Phosphorus increases tiller initiation Percent in nitiation Goos and Johnson, 1996 Hettinger, ND Olsen P = 1 ppm lb P 2 O 5 /A placed with the seed T T1 T2 T3 T4 ST Tillers 3 Fixation by Fe, Al & Mn Fixation of Added P Fixation by hydrous oxides of Al and Fe Calcium phosphates Available P Source: NC Brady, 199. The Nature and Properties of Soils. Soil ph 6

7 2 8 Hay Price, $/tonne Hay Fertilizer 2%? 1%? Fertilizer Price Index, 1992= Average prices paid for hay and fertilizer (N, P, and K) by farmers in the USA, (USDA-NASS). Corn response to P as predicted by soil P saturation index Pellerin, et al., 26. Can. J. Soil Sci. 86: Soil Test Categories Probability of response to applied nutrients at different soil test levels Response Category Probability of response Rating ON Olsen-P, ppm Example: P for corn QC** M3-P, kg/ha QC M3-P/Al, % High (HR) >6% L Medium (MR) 4-6% M Low (LR) <4% H Rare (RR) <2% VH No or Negative (NR)* * E >61 >251 >2 *adding nutrients to soils with these levels of nutrients may reduce crop yields or quality by interfering with the uptake of other nutrients. **for sweet corn 7

8 Crop response to applied P at a given level of soil test P can depend on: Amount & type of clay Application timing Crop cultivar Other nutrients Soil aeration Soil compaction Soil moisture Soil organic matter Soil ph Tillage & weather Approaches to P Fertilization Sufficiency approach: Apply P to maximize net returns to fertilization in the year of application Strategy: fertilize only when there is a good chance that a profitable Soil test P level yield response will be realized Soil test levels kept in lower, responsive ranges Normally adopted on land leased for short periods of time or when cash flow is limited ive yield, % Relat Approaches to Fertilization Build and maintenance approach: Remove P as a yield-limiting variable Strategy: apply extra P (more than crop removal) Soil test P level to build soil tests to levels that are not yield-limiting Soil test levels kept in higher, non-responsive ranges Normally adopted on owned land or land leased for longer periods of time ive yield, % Relat 8

9 Build-up & Maintenance vs. Sufficiency Why Broadcast? Can apply large amounts conveniently Ideal for building soil fertility Minimizes risk of fertilizer injury On fields of low fertility, banded starter P may not be adequate for maximum yield Combinations of broadcast and band applications produce the highest yields on low testing soils Band Application Overwhelms soil fixation capacity Places nutrients near the seedling Roots intercept early and proliferate near the band Including ammonium-n, slows P fixation and lowers ph near the root to improve both P and micronutrient availability Favors the crop over the weeds Keeps nutrients away from the surface Reduces runoff P concentrations 9

10 Seed Placement: Small Amounts, Liquid or Granular P 2 O 5 rate, Corn yield, 1 kg/ha t/ha Mean of two hybrids at each of two Ontario sites; seed-placed Rate, kg P 2 O 5 /ha Corn yield, 2 t/ha Liquid 3 Granular MAP, Mean of three Ontario sites 3 Mean of three products: 1-34-, , Soil test P ranged from 3 (L) to 35 (VH) When soil test P was L to M, seed-placed P was not sufficient Source: Lauzon et al., 1995 Phosphorus in Starter Fertilizers Greg Stewart, OMAFRA 5x5 IF = placed 5 cm beside and 5 cm below the seed row = in-furrow or seed-placed = placed with the seed in the seed furrow 1

11 Ontario Starter Fertilizer Trials, 29 Elora (early May planting) Ilderton 224 kg/ha 6 Broadcast; 168 kg N/ha Conventional Tillage P=8(L) K=68(M) P=25(H) K=136(H) Treatment Yield, t/ha Yield, t/ha No Starter 1.5 No Starter L/ha 5x L/ha L/ha 5x (IF) L/ha IF 1.6 MAP (split) 1.8 MAP@84 kg/ha 5x (5x5) 1.9 MAP@84 kg/ha 5x5+UAN@93 L/ha 5x (+ UAN) 1.9 MAP@84 kg/ha spring broadcast 1.5 MAP 28 kg/ha IF + 56 kg/ha 5x L/ha IF kg/ha 5x Source: Greg Stewart, OMAFRA Ontario Starter Fertilizer Trials, Elora 29 Soil Test P=9(L) K=66(M) late May planting Corn grain yield, t/ha No till Spring Field Cultivate Spring Strip till No starter 67 kg/ha L/ha kg/ha Source: Greg Stewart, OMAFRA 11

12 Ontario Starter Fertilizer Trials, Elora 28 Soil Test P=12(M) K=6(L) kg/ha Starter Fertilizer Corn Yield t/ha No starter L/ha 5x L/ha IF L/ha IF L/ha 5x L/ha 5x L/ha IF kg/ha 5x kg/ha 5x kg/ha 5x L/ha 5x kg/ha 5x L/ha IF kg/ha 5x kg/ha 5x Source: Greg Stewart, OMAFRA Ontario Tillage x Starter Fertilizer Studies Alma, Ancaster, Wellington, Loam to silt loam soils Bill Deen, Greg Stewart, John Lauzon Tillage x Fall Fertilizer x Spring Starter Experiment 4 x 4 x 5 factorial Plots 1' wide by 7' long All plots received 3 lb/a starter N as UAN 12

13 No-till; No Fall Fertilizer Only UAN in 5 gal/a plus -2-2 in 2x2 15 lb/a Alma, Ontario 23 Yie eld, t/ha No-Till Zone-Till Disc-ripper Plow Fall tillage STP = 16 (M); STK = 58 (L) check L/ha 5x5 34 kg/ha x2 5x5 68 kg/ha Alma, Ontario ld, t/ha Yiel Fall Rate, kg/ha P 2 O 5 and K 2 O check L/ha 5x5 34 kg/ha x2 5x5 68 kg/ha STP = 16 (M) STK = 58 (L) 13

14 Corn Responses to Starter Alma 23 was one of 9 site years Both P and K apparently limiting? 8 of the 9 showed far smaller responses 5 more showed starter NP benefits in no till but not in plowed soil 3 with high soil tests showed no response to applied fertilizer CONCLUSION: Consider soil test levels, other nutrients and tillage when making decisions on starter fertilizer Cropland P Balance Trends P 2 O 5, tonnes Phosphorus Balance Quebec P 16, Balance in Quebec 14, 12, 1, 8, 6, 4, 2, Fertilizer Manure Crop

15 P 2 O 5, tonnes 12, 1, 8, 6, 4, Phosphorus Balance Quebec Fertilizer Recoverable Manure Crop 2, P P removal exceeds use in much of the Corn Belt U.S Phosphorus removal to use ratios in the Northeastern USA, 1987 and

16 Soil Test P median Bray-P1 equivalent Distribution of soil test P bon, riche, + riche pauvre moyen % of samples Soil Test P (M3) in QC pauvre moyen bon riche + riche Data source: La Coop fédérée Agro-laboratory 16

17 % of samples P/Al ratio (M3) in QC kg P 2 O 5 /ha Data source: La Coop fédérée Agro-laboratory Regulations regarding P Low-P lawn fertilizers Nutrient management plans P index in the USDA-NRCS 59 Adaptive, science-based management 4R Nutrient Stewardship Right Right Rate, Right Time & Right Place Linking practices to science for sustainability performance 17

18 Buda et al., 29. J Environ. Qual. 38: Summary 1. P is essential to plants for energy in metabolism 2. P is retained in soils and slowly available 3. Soil testing determines the amount of P to include in a starter, and the placement of the starter 4. With surplus P declining and in some places disappearing, soil test P may be declinging in some areas 5. 4R Nutrient Stewardship selects the right source, rate, time & place for optimum economic, social, and environmental sustainability Comments Welcome nane.ipni.net 18