Comparison between conventional and organic rice production systems in Northern Italy

Transcription

1 CASE STUDY 2 Comparison between conventional and organic rice production systems in Northern Italy

2 INTRODUCTION & AIMS 1) To assess the environmental profile of organic rice production (ORP) system in Northern Italy 2) To identify the key processes from an environmental point of view 3) To compare the environmental impact of organic (ORP) and conventional (CRP) rice production systems. QUESTIONS: What is the environmental impact for 1 ton of grain (14% moisture) from ORP system? What are the processes most responsible for this impact? TRAD Compared to traditional rice production system (characterized by higher yield) which rice system show better environmental performances?

3 ORGANIC RICE PRODUCTION SYSTEMS (ORP) In 2014, the rice area dedicated to organic rice was 9,528 ha (4.3% of the overall rice area) with a total production of 57,070 t (3.5% of the rice production). - Respect to CRP, the ORP is characterized by great yield variations and, on average, by yield reductions of about ⅓ - ½. + The application of organic fertilisers instead of the mineral ones can be beneficial for soil - Organic fertilisers are not always easy to find and enhance CH 4 emissions in anaerobic conditions + The ban of pesticides - Weed management requires intensive mechanical control

4 THE CASE STUDY Rice farm located in Lomellina (Lombardy) where organic rice has been cultivated over about 70 ha in the past 15 years. 19 paddy rice fields in Average yield (5.3 t ha-1 of rice grain at 27% of moisture corresponding to 4.5 t ha-1 at commercial moisture) Only ORP system and no CRP. Paddy field Area Grain yield (ha) (t ha-1)

5 Green Manure SOWING VETCH RYEGRASS S Crop Management MECHANICAL WEED CONTROL (4 times) FLOODING W Field Preparation - Sowing ORGANIC FERTILIZATION C PLOUGHING HARROWING SOWING Harvest and storage HARVESTING TRANSPORT 2.45 km S DRYING ORP SYSTEM DESCTIPTION In autumn, a mix of vetch and ryegrass is sown; in the following May the biomass is incorporated into the soil. Rice sowing is carried out with a precision seeder (220 kg/ha of seed - depth of 5-6 cm) after tillage operations. Weed control is performed using a spring tine harrow (4 interventions). After it, the rice fields are flooded and no aerations are scheduled. The flooding ends only at the beginning of September. Harvesting operations carried out with self-propelled harvester and rice paddy is transported to the farm. The straw is left into the soil

6 SYSTEM BOUNDARY The following activities were included in the analysis: manufacture and use of the agricultural inputs (e.g., fuels, seed, fertilizers and agricultural machines), maintenance and final disposal of machines emissions related to organic matter decomposition, fertiliser application and fuel combustion INPUT OUTPUT Seed, Diesel fuel, Lubricant, Tractor, Implements. Green manure Emissions in water, air and soil CH 4, N 2 O, NH 3, fuel combustion emissions Seed, Diesel fuel, Implements, Tractor Lubricant, Org.Fert Soil tillage & Sowing Emissions in water, air and soil fuel combustion emissions Diesel fuel, Tractor, Implements, Water Lubricant. Crop management Emissions in water, air and soil CH 4, N 2 O, NH 3, fuel combustion emissions Diesel fuel, Lubricant, Tractor, Implements. Harvesting & Storage Emissions in water, air and soil Combustion emissions emissions Grain and straw

7 INVENTORY DATA: Crop cultivation Section (A) Green manure (B) Soil Tillage & Seeding (C) Crop Management (D) Harvesting & Storage Month Field Operative Tractor FC Input Time Operation machine kw kg kg ha -1 Product Amount h/ha Data source 140 kg ha -1 October Sowing Seeder Seeds ryegrass kg ha -1 vetch April Organic Manure fertilization spreader Compost 22.5 t ha -1 (b) 5.05 April Ploughing Plough Rotary April Harrowing Farm surveys harrow and farmer May Sowing Seeder Seeds 220 kg ha -1 rice 0.86 interviews May 5 Mechanical Harrow (average June weed control tines data for June Water Water m eleven September management - paddy fields) September Harvest Combine harvester t ha -1 (27% of moisture) September Transport Trailer September Transport Trailer September Drying Dryer Weed control is perforemd thanks to 5 mechanical intervention until the crop emergence and, after that, with flooding. A grain yield 4.50 t/ha at commercial moisture (5.3 t/ha at 27% of moisture, about 33% lower respect to conventional rice) was considered. Sistema d Informazione Nazionale sull Agricoltura Biologica, 2015 (

8 INVENTORY DATA: Methane emissions Rice cultivation is responsible for considerable emissions of GHG in particular of methane produced during the decomposition of organic matter in anaerobic conditions. As regard to the CH 4 emissions, the methodology proposed by the IPCC was considered. Methane emissions are evaluated considering: Amount of organic matter introduced into the soil STRAW ORGANIC FERTILIZER (COMPOST) GREEN MANURE Number of aerations during the crop cycle (no aerations are scheduled) Duration of flooding CH 4 emissions with higher application of organic matter and longer flooding. CH 4 emissions with aerations, reduction of flooding, reduction of organic matter application.

9 ALTERNATIVE SCENARIOS BS no aeration during flooding, 22.5 t/ha of compost (transported for 60 km) AS 1 Introduction of two aerations during flooding - 10% yield and straw production. AS 2 no compost, 66.7 t/ha of cattle manure transported for 10 km AS 3 no compost, 88.8 t/ha of cattle manure transported for 5 km AS4 no compost, 9.1 t/ha of dried poultry manure transported for 45 km AS5 straw collected and sold economic allocation between straw (6.1%) and grain (93.9%) increase of compost (+2.9 t/ha) due to higher N removal Organic fertiliser CH 4 Scenario Nitrogen Transport emission Type Amount content Distance (kg ha -1 ) BS Compost 22.5 t ha kg t -1 of fresh matter 60 km AS1 Compost 22.5 t ha AS2 Cattle manure 67.5 t ha kg t -1 of fresh matter 10 km AS3 Cattle slurry 88.8 t ha kg t -1 of fresh matter 5 km AS4 Dried poultry manure 9.1 t ha kg t -1 of fresh matter 45 km AS5 Compost 25.4 t ha kg t -1 of fresh matter ] 60 km Green manure is considered in all the scenarios AS5 Windrower (coupled with a tractor of 90 kw; diesel cons kg ha -1 ) and baler (coupled with a tractor of 120 kw, diesel cons kg ha -1 ) 4.3 t ha-1 of straw are collected; 12.7 kg of nitrogen per ton of straw - dry matter

10 ENVIRONMENTAL IMPACT ASSESSMENT As regard to ORC system the following 9 environmental impacts were evaluated: Climate change (Global warming potential) Ozone depletion Particulate matter formation Photochemical oxidant formations Human toxicity, cancer effects Acidification Terrestrial eutrophication Freshwater eutrophication Marine eutrophication Freshwater ecotoxicity Mineral, fossil & ren resource depletion ILCD 2011 Midpoint V1.01

11 Impact Category Unit Score Climate Change kg CO 2 eq Ozone Depletion kg CFC-11 eq Human Toxicity CTUh Particulate Matter formation kg PM2.5 eq 2.38 Photochemical oxid. Form. kg NMVOC eq Acidification molc H+ eq Terrestrial Eutrophication molc N eq Freshwater Eutrophication kg P eq Marine Eutrophication kg N eq Freshwater Ecotoxicity CTUe And now? RESULTS: Absolute values FU =1 t OF RICE GRAIN (14%) Min.Fossil Resourse Depl. kg Sb eq For maize grain in the same area, CC range from 200 to 350 kg CO 2 eq/ha However, besides the absolute values, it is important also TO IDENTIFY which processes, over the whole production system, are most responsible (hotspots) for the environmental impact of organic rice production. The hotspot identification is the prerequisite for the development of solutions able to reduce the environmental impact.

12 Relative contribution (%) Mechanisation of field op. Ryegrass seed Vetch seed organic Compost, production Rice seed Grain drying Fertiliser emissions Methane emissions CH 4 emissions are responsible for about 42% of CC CC OD HT PM POF TA TE FE ME FEx MFRD Compost production involves high emissions related to OM decomposition as well as energy consumption and N-P emissions Emissions due to fertilizers application are hotspots for eutrophication and acidification and particulate matter formation RESULTS: Hotspots Seed production (both for green manure and rice) are relevant for freshwater ecotoxycity Mechanization of field operation is an hotspots for MFRD, OD and HT mainly due to emission from fuel combustions

13 BS AS 2 - Cattle manure AS3- Cattle slurry CC 100% MFRD 90% 80% 70% FEx 60% 50% 40% CC AS1 - Two aerations AS 5 - Straw Collection AS 4 - Dried poultry manure OD HT COMPARISON AMONG THE ALTERNATIVE SCENARIOS RESPECT TO BS: AS1 reduces CC (thanks to the reduction of CH 4 emission) but increases all the other impact categories due to the lower yield. AS2 and AS3 are the two best scenarios except than for CC. AS2 is slightly better thanks to lower transport distance and lower CH 4 emissions ME FE TA POF AS4 shows lower impact for all the impact categories. In particular, CC is reduced of 50% because a lower amount of organic matter is used as fertilizer. Respect to the use of manure and slurry, the impact is higher for HT and OD due to the poultry manure drying. TE AS5 reduces CC thanks to the reduction of CH 4 emission. Despite the allocation to the straw of 6.1% of the total impact, for the other impact categories this scenario shows similar results to BS. For MFRD the impact is slightly higher than in BS due to the diesel fuel consumption for straw collection.

14 Comparison beetween CRP and Organic CRP: average yield 6.8 t/ha, 1 aeration, no green manure, fertilization with mineral fertiliser and urban sewage sludge, 3 applications with pesticides (2 herbicides and 1 fungicide) IT DEPENDS ON: ORP CRP Impact category Cultivation practice Yield Climate For impact categories affected by pesticide application such as FEx, the ORP achieves considerably better performances ( 94%) due to the avoided application of plant protection products For other impact categories the environmental impact of ORP is higher than CRP. For CC, the environmental impact related to ORP is 5 times higher than in CRP, this differences is related to higher application of organic fertiliser, lower yield (-30%) and higher diesel fuel consumption for mechanical weed control.

15 Comparison beetween CRP and Organic

16 LCA and AGRICULTURAL SYSTEMS Holistic approach allows to consider simultaneously more environmental effects Some important environmental effects (e.g., loss of biodiversity) are really hard to be measured and characterize. Important for ORP? Several information about crop cultivation can be summarized in a few environmental indexes Complex systems can be compared with the same methodology. LCA is standardized by specific ISO standards and it is the most applied method for environmental impact assessment. Measurement of inventory data are time and cost expensive, some data (e.g., nutrient leaching, methane emissions from soil are really difficult to measure) There are wide needing of accurate models for estimation of emissions (e.g., engine exhaust gases, N and P compounds, a.i. from pesticides, methane field emissions), soil carbon content, etc. Without reliable inventory data the outcomes of the assessment are worthless and untrustworthy The reliability of an LCA study strongly depends on the reliability of the collected inventory data.

17 CONCLUSION The substitution of mineral fertiliser with organic one involves considerable environmental impact due to their production and transport and due to emissions into air, soil and water. When available, the use of other organic fertiliser instead of compost can involve a improvement of environmental performance of ORP. Respect to conventional rice production systems, the reduction of pesticide application allows to ORP achieves better performances ( 94%) due to the avoided application of plant protection products For the other environmental effects, the reduction of yield deeply affect the environmental performances. Future improvement of the cultivation practice for organic rice production and, the consequently yield increase could reduce the differences between ORP and CRP.

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19 ALTERNATIVE SCENARIOS: Inventory data Organic fertiliser CH 4 Type Amount Main Inputs & Nitrogen Transport emission Spreading Outputs content Distance (kg ha -1 ) BS Compost 22.5 t ha -1 6 kg t -1 of diesel fuel [b] ; kg t 140 kwh t -1 of of manure spreader (coupled with a tractor 60 km AS1 Compost 22.5 t ha -1 fresh matter electricity of 100 kw; diesel cons kg ha -1 ) [b] AS2 Cattle 5.0 kg t 67.5 t ha -1 - of manure spreader (coupled with a tractor manure fresh matter [d] of 100 kw; diesel cons kg ha -1 ) 10 km AS3 Cattle 3.8 kg t 88.8 t ha -1 - of slurry tank (coupled with a tractor of 120 slurry fresh matter [e] kw, diesel cons kg ha -1 ) 5 km AS4 153 kwh t Dried of heat from fertiliser spreader (coupled with a nat. gas; 110 kwh t poultry of 37.2 kg t 9.1 t ha of -1 tractor of 90 kw; diesel cons electricity; kg t -1 fresh matter [c] manure kg ha of NH 4 emission ) [c] 45 km AS5 Compost 25.4 t ha -1 6 kg t -1 of diesel fuel; 140 kwh t -1 of electricity AS1-10% of grain yield 15.0 kg t -1 of fresh matter [b] fertiliser spreader (coupled with a tractor of 100 kw; diesel cons kg ha -1 ) 60 km Green manure is considered in all the scenariosaw are collected; 12.7 kg of nitrogen per ton of straw - dry matter AS5 Windrower (coupled with a tractor of 90 kw; diesel cons kg ha-1) and baler (coupled with a tractor of 120 kw, diesel cons kg ha-1) [e]. 4.3 t ha-1 of straw are collected; 12.7 kg of nitrogen per ton of straw - dry matter [g]