International Conference on Enhanced-Efficiency Fertilizers

Transcription

1 International Conference on Enhanced-Efficiency Fertilizers An IFA-New Ag International Event March 2010 Hotel Hyatt Regency, Miami, FL, USA NITRIFICATION INHIBITORS AND THE IMPACT OF THEIR USE, WITH SPECIAL REFERENCE TO FERTIGATION Georg EBERT COMPO EXPERT, Germany

2 Nitrification inhibitors and the impact of their use, with special reference to fertigation IFA/NewAG Miami 23 March 2010 Georg Ebert, COMPO EXPERT, Münster Nitrification inhibitors Agenda DMPP - Mode of action Environmental effects Gaseous N losses NO 3 leaching Physiological effects of NH 4 Effect on crop yield and quality Summary 1

3 Nitrification inhibitors DCD Dicyandiamide (Europe) Nitrapyrin 2-chloro-6-(trichloromethyl)-pyridine (US) (N-Serve) DMPP 3,4-dimethylpyrazol-phosphate Heterocyclic N compounds S compounds Urea derivates Acetylene derivates Ammonium thiosulfate.. DMPP DMPP = Dimethylpyrazolephosphate H 3 C C HC N H CAS-Nr.: form: powder colour: white to grey ph: 2.5 3,0 (132 g/l, 25 o C) melting point: approx 165 o C density: 1.51 g/cm 3 solubility: 132 g/l, 25 o C (water) log Pow: 1.26 CH 3 C N H 3 PO 4 BASF development ( ) Derived from the group of pyrazoles Highly effective even at low application rates Breakdown depending on temperature Not present in harvested goods or other residues Highly specific for Nitrosomones Bacteriostatic, not bactericide 2

4 DMPP Mode of action NH 4 + NO 2 - NO - 3 O 2 O 2 Nitrosomonas Nitrobacter DMPP Mode of action DMPP Specific inhibition of the enzyme ammonium mono-oxygenase NH + 4 NO - 2 STOP Nitrosomonas O 2 Nitrobacter NO - 3 3

5 Without Inhibitor Concentration Concentration DMPP Mode of action DMPP Specific inhibition of the enzyme ammonium mono-oxygenase NH + 4 NO - 2 STOP Nitrosomonas O 2 Nitrobacter NO - 3 NO 3 NH 4 Time NH 4 NO 3 Time With Inhibitor Gaseous N losses Environmental effects Gaseous N losses NO 3 leaching 4

6 N 2 O emissions (kg ha -1 a -1 ) N 2 O Emissions from agricultural land Influence of DMPP on N 2 O emissions (denitrification) 3-years field trials in Germany Control + DCD Mean From: Weiske, Benckiser, Herbert and Ottow. Biol Fertil Soils (2001) 34: Physiological effects of NH 4 fertigation H + Charge compensation Prevailing NH 4 -absorption leads to acidification of the rhizosphere Prevailing NO 3 -absorption leads to alkalinization Photo: Römheld, University of Hohenheim, Germany 5

7 N form and nitrification inhibitor improve trace element uptake from the soil (Trials with beans, sandy loam, P source: rock phosphate) ph-value Nutrient absorption (µg/m root length) N-form Far from roots Rhizosphere P Fe Mn Zn Cu K NO NH NH 4 + NI Ammonium nutrition: Rhizosphere effect due to increased cation absorption Acidification due to ammonium fertilization NH O 2 NO 3- + H 2 O + 2 H + From: Thomson et al. (1993) J. Plant Nutr. 16, NH 4 -N improves cytokinin and flower bud formation in apple trees Shoot growth, flower induction and cytokinins in xylem exudate of apple root stock M7 as affected by the form of N supply Form of N-supply Shoot length [cm] No. lateral shoot (spurs) Flowering buds [% of emerged] Cytokinins [nmol/100 g shoot fresh wt] NO 3 -N NH 4 NO NH 4 -N From: Gao et al. (1992) J. Amer. Soc. Hort. Sci. 117,

8 Summary of physiological effects More balanced NH 4 to NO 3 supply to roots. A more balanced cation to anion uptake by the plant less spending of metabolic energy for nutrient uptake The NH 4 part of N uptake is already reduced no metabolic energy (NADH 2 ) needed for reduction Positive effects on phytohormones (e.g. cytokinines) and polyamine metabolism (reasonable presumptions) Relative acidification of the rhizosphere compared with the bulk soil enhanced availability of nutrients Effect on crop yield and quality 15 N Trials in Citrus Trees Trials on Melon produced in greenhouse 7

9 Nitrogen Efficiency in Citrus using 15 N Distribution of 15 N after application of NH 4 NO 3 alone or along with DMPP Fertigation frequency: 30 days per month Tree 15 N-tree NH 4 NO 3 NH 4 NO 3 N-Tree 22% 30% Soil 15 N-NH 4 15 N-NO 3 15 N-org. 15 N-leaching NH 4 -N 2% 6% NO 3 -N 52% 44% Org.-N 10% 12% N-Losses 14% 8% In cooperation with the Valencia Institute of Agronomic Research (Spain) Nitrogen Efficiency in Citrus using 15 N N use efficiency related to fertigation frequency Presented in the X Spanish-Portuguese Mineral Nutrition Symposium 25% 15% DMPP is more effective in systems with high frequency fertigation 5% 1 x month 2 x month 8 x month 30 x month Fertigation frequency 8

10 mg NO3 per plot Reduction of N losses in an orange fertigation system (Trials in Valencia, Spain Fertigation every 20 days using (NH 4 ) 2 SO 4 (AS) + NH 4 NO 3 (AN), total:12 g N per tree) N found in drainage water Control 4000 AS/AN AS/AN 3000 The use of DMPP reduces N-losses by 50 % compared to conventional fertilization Yield increase in clementine trees (Trials at I.V.I.A, Valencia, Spain, , 500 trees/ha; 400 g N/tree; AS 0.5%) AS 4x per week AS 2x per week AS 1x per week Kg/tree Fruit weight No of fruits per tree

11 Yield (kg m -2 ) Optimization of N fertigation in melon NO 3 concentration (mg/l) in soil solution at 30 cm and 60 cm soil depth 800 Planting: cm Harvest: Conventional NovaTec 200 Crop: Melon, Piel de Sapo, planted 2 x 1.3m Duration: 115 days, daily irrigation Soil: ph 8.6, 23% active CaCO 3, low organic matter, slightly saline cm In cooperation with CIFACITA Research Institute. Murcia, Spain Optimization of N fertigation in melon CIFACITA Research Institute. Murcia. Spain Higher fruit yield and more high quality fruits Quality 47% - 1A 38% - 2A 15% - low Quality 52% - 1A 35% - 2A 13% - low 0 Conv 10

12 % of plants died off N content in leaves (% of DM) (protein-n) Optimization of N fertigation in melon CIFACITA Research Institute. Murcia. Spain Higher N uptake effciency 6 5,5 Conv 5 4, Optimization of N fertigation in melon CIFACITA Research Institute. Murcia. Spain Plants survived high temperature periods and showed resistance to Melon collapse caused by the fungus Acremonium sp. due to better root growth Conv Harvest 11

13 SPAD values Effect of NovaTec21 on table grape canopy Cv. Red Globe, sandy soil Copiapó, Río Blanco Export, Chile, 2005 NovaTec solub 21 Urea NH 4-N and NI improve leaf colour of grapevines Urea NovaTec solub 21 Summary Increase in yield and N efficiency Reduced NO 3 leaching Lower N losses Better N supply Reduced gaseous N losses Better P and trace element uptake Effects on plant physiology: Energy requirement, phytohormones, polyamines ph reduction in the rhizospere Moderate and continuous N availability to roots Partly NH 4 nutrition Inhibition of nitrification Advantages of ammonium fertilization together with nitrification inhibitor 12