Potassium Research at Uruguay

Transcription

1 Potassium Research at Uruguay Fernando O. García IPNI Cono Sur Mónica Barbazán Facultad de Agronomía Universidad de la República

2 IPNI is a not-for-profit, scientific organization We provide a scientific voice for the world s fertilizer industry; independent, and scientifically credible Established on the basis of defining appropriate use and management of plant nutrients The mission of IPNI is to develop and promote scientific information about the responsible management of plant nutrition for the benefit of the human family

3 IPNI Program Areas 32 scientists + 30 support staff Eastern Europe & Central Asia Latin America Southern Cone IPNI Programs The International Plant Nutrition Institute (IPNI) is a not-for-profit organization dedicated to the development and promotion of science for the responsible management of crop nutrition

4 Members EECA Staff Svetlana Ivanova VP EECA and Regional Director Affiliates Vladimir Nosov Deputy Director Alexandra Erofeeva Office Assistant

5 Bolivia Latin America Southern Cone program Argentina, Bolivia, Chile, Paraguay, and Uruguay Paraguay Fernando O. Garcia Regional Director Chile Argentina Uruguay Adrian A. Correndo Assistant Agronomist Area of 5220 km 2 Population of 75 million people More than 70 million ha of crops and pastures Laura N. Pisauri Secretary - Administration

6 Midwest and Central Great Plains Russian Plains China Pampas and Chaco regions

7 Bolivia Paraguay Russian Federation Chile Argentina Uruguay Most of the cropland in the Southern Cone is located above the parallel S40 o, north through the parallel S10 o, including temperate to subtropical conditions, with humid (towards the east) to arid (towards the west) conditions.

8 Paraguay Uruguay Chile Argentina Brazil S 30 0 Located in the southeastern region of South America Uruguay Atlantic Ocean S 35 0 Population of 3.3 million people Area of 176,000 km 2. Agriculture contributes to 11.8% of the gross domestic product (GDP), almost half from livestock and half from crop and vegetable production. Agricultural products represent 75% of the total exportations, mainly soybean, beef cattle, dairy products, forestry, and rice.

9 Uruguay: Original distribution of soil exch. K Brazil meq/100g ppm < >235 Argentina Source: Califra and Barbazán, unpublished

10 Uruguay: Cropped area by the seven main crops during the period Source: DIEA-MGAP (2015) Rice Area, thousand ha Soybean Sorghum Sunflower Maize Barley Wheat Intensification of cropping systems, from crop-pasture rotations to continuous annual cropping under no-till systems Annual cropped area increased from 700 thousand to + 2 million ha Soybean and wheat sown on 67% and 20% of the area Current index of 1.5 crops per year

11 Potassium balance in agriculture of Uruguay 1990, 2000, and 2010 Source: Mancassola and Casanova (2015) Year Balance (ton K) K fertilizer value (thousand U$)

12 K in Uruguay by early 2000`s farmers have observed deficiency symptoms

13 Uruguay Exploration of K deficiencies in the western region Problems detected in 2005/06 Field trials in 2006/07 and 2007/08

14 Uruguay: K in maize Cano et al. (2007/08) - Young (Uruguay) (La Macarena)

15 K in Uruguay Average grain yield responses Grain yield (kg/ha % % +14% % Barley Wheat Soybean Maize Check 30 K2O 60 K2O 120 K2O 240 K2O Source: C.Bautes, M.Barbazán, L.Beux,

16 Exploration of Responses to Potassium in Western Uruguay Crops: barley, wheat, corn, soybean, sorghum, sunflower, canola, pastures All in commercial farms. Manual fertilizer application & harvest.

17 K calibration for Uruguay Barbazán et al. (2011) 34 field trials from Bautes and Beux; Garcia and Quincke; and Cano and col. Critical level at 0.34 meq/100 g (133 ppm K)

18 Relationship between relative crop yield (RY) and soil test K (STK; 0-20 cm) in Uruguay Source: Barbazán et al. (2010, 2014) Critical level at ppm

19 Soybean grain yields according productivity and relationship with soil and plant variables (178 commercial fields) Median (thin center line), and percentiles (10, 25, 75 and 90) for yield zafras 2009/10; 2009/10 and 2010/11 seasons Bordoli, Barbazán, Rocha kg/ha STK 0.76 cmol kg -1 K leaves 2.4% Source: Bordoli et al. (2012) Soybean yield (kg ha -1 ) Rend. grano soja (kg/ha) Soil ph: 6.0 SOM: 4.1% K: 0.76 cmol kg -1 Ca: 20.1 cmol kg -1 Mg: 2.4 cmol kg -1 Exch. Ac cmol kg -1 Plant 4.5%N 0.3%P 2.4%K Soil ph: 5.8 SOM: 3.4% K: 0.61 cmol kg -1 Ca: 16.8 cmol kg -1 Mg: 2.2 cmol kg -1 Exch. Ac cmol kg -1 Plant Planta 4.4%N 0.3%P 2.1%K Soil ph: 5.3 SOM: : 3.6% K: 0.27 cmol kg -1 Ca: 8.4 cmol kg -1 Mg: 1.7 cmol kg -1 Exch. Ac cmol kg -1 Plant 3.9%N 0.3%P 1.7%K > < kg/ha STK 0.27 cmol kg -1 K leaves 1.7%

20 Rate of K 2 O equivalent (kg K 2 O ha -1 per 0.1 cmol kg -1 soil) for different soil types of Uruguay under controlled incubations Source: Barbazán et al. (2014) K 2 O equivalent (kg K 2 O ha -1 per 0.1 cmol kg -1 soil ) Sed. L-arc/Bas. (1) Sed. arc./cal. de Bco (1) Holoc./Dol. (1) Sed. Lim. (calc.)/fb (9) Sed. Ac-Ar (L- Ac)/Cret. (5) B. Crist. (1) Sed. L-Ac/BC (9) Sed. Francos (L- Ac)/FB (7) Fm Salto (1) Soil type Field work has shown that rates of K needed to increase 0.1 cmol kg -1 soil of exchangeable K varied from 127 to 526 kg K 2 O ha -1, averaging 231 kg K 2 O ha -1 (4.9 kg K ha -1 per ppm K).

21 Exch K (cmol c kg -1 ) Exch K (cmol c kg-1) Temporal variation of exchangeable K (Exch K, STK) after harvest of soybean and maize Source: Barbazán et al. (2011) /03/10 02/05/10 21/06/10 10/08/10 29/09/10 18/11/10 07/01/ b) Maize Sampling date a) Soybean /3/10 2/5/10 21/6/10 10/8/10 29/9/10 18/11/10 7/1/11 Sampling date STK varied at different depths depending on K release from crop residues.

22 K in dry samples/ K in moist samples Relationship between the STK in dry samples/stk in moist samples with STK in moist samples Iowa, USA Barbagelata and Mallarino (2012) K in moist samples (meq/100g) K in dry samples/k in moist samples Uruguay Barbazan et al. (2014) K in moist samples (meq/100g) STK would be overestimated when determined in dry samples at the low STK range. This would be one possible cause of the poor calibration observed in some datasets

23 Relationship of dry matter production with exchangeable K and K extracted with NaTPB Biomass production (g DM/pot) y = 14,5x + 2,29 R² = 0,81 y = 5,97x + 3,19 R² = 0, STK (meq/100g) K int K NaTPB Source: Nuñez (2014) The NaTPB method extracts exchangeable K plus a proportion of nonexchangeable K It is considered promising to estimate soil K reserves and to monitor STK evolution

24 Long term experiments 240 K 2 O 0 K 2 O Control

25 Outcomes of K Project 29 publications in congresses, symposia, and peer-review publications K Symposia in 2010 and 2013 More than 15 specific presentations at meetings Several field visits 10 Undergraduate thesis 3 Master thesis 1 PhD dissertation

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27 Nutrient importations at Uruguay in the period Source: (DIEA-MGAP, 2015) Nutrients (metric t) K2O P2O5 N K 2 O importations at Uruguay have gone from 9,000 t in 2003 to 146,000 t in 2013

28 Some conclusions K deficiencies in soils of Uruguay developed from cropping intensification and negative nutrient balances Research has shown high probability of fertilization responses with STK below cmol kg -1 ( ppm; 0-20 cm depth) Recent research look to improve the predictability of STK calibration and develop guidelines on K fertilization management Future research and experimentation will have to focus on the relationship of K dynamics with soil mineralogy and physical properties, and with changes in cropping systems and soil management history in the medium and long term. Potassium use efficiency depends on understanding of K dynamics in the soil-plant system, as well as of crop and soil responses to soil fertility management.

29 Спасибо!! Thank you!! Muchas gracias!! Fernando O. Garcia IPNI Southern Cone