Photosynthetic Bacteria for Sustainable Rice Production

Presented By: Samir Ebson TopnoENS 275UPLB, Philippines

•1960-1970 green revolution resulted dramatic yield increase•Asian countries showing signs of fatigue in productivity gains(Kesawan & Swaminathan, 2008)•Intensive agriculture led to loss of soil health, depletion of freshwater resources and agro-biodiversity. •Rice staple food for 3.31 billion people out of world population 6.22 billion (FAO, 2002)•Rice – staple food low-income and developing countries.

Introduction

•fertilizer costs 30-40% in the rice production•Cost of urea 38.29 % increased since 2006(www.nscb.gov.ph, 2008)•High Energy consuming-78,230 kJ/kg of nitrogen from production to apply (Helsel, 1992)•High content of hydrochloric and sulfuric acid in chemical fertilizers•Destroyed nitrogen fixing organism in the soil

Problem with Chemical fertilizers

•50 % of applied nitrogen lost to the environment (MA, UNEP, 2005)•Unabsorbed chemical fertilizers travel to water resources and cause eutrophication•Artificial nitrogenous fertilizers largest contributors of CH₄ and N₂O•Threatened human health (Verhoog and others, 2003)•Excessive nitrogen application led to pest problem (Jahn, 2004)

•Wide diversity of N₂ fixing organisms (diazotrophs)•Free living – Rhodospirillum, Bradyrhizobium and cyanobacteria etc•Inhabit flood water, surface soil etc

Nitrogen Fixing Bacteria

Evidence of Nitrogen fixation by photosynthetic bacteria

•Experiment done in rice field of valencia, Spain•In situ nitrogen fixing rates estimated by acetylene reduction method •Resulted ratio of 3.9 mol of acetylene reduction per mol of N₂•N₂ fixation rate calibrated 40.5 kg of N/ha/crop on the rice soil system•3.93 Kg N/ha/crop was fixed in the rice plant

•Rhodospseudomonas palustris increased rice yield (Harada and others, 2005)•Use of EM is more economical and environmental friendly•Successful transition from conventional farming without initial decrease (Minami and Higa, 1994)•Without cultured cyanobacteria can fix 10-40 kg N/ha/year (ACIAR, 2008)

Evidence of Nitrogen Fixations by Bacteria

Production Factors

Conventional Farming Methods

A B C D

Chemical fertilizers

21, 094 0 0 0 0

Pesticides 13,671 0 0 0 0EM 0 13,750 12,250 20,000 18,778Organic Matter 0 2,450 7,515 1,682Total cost (Yen) 34,765 16,200 19,765 20,000 20,460Relative cost (%) 100 46.6 56.9 57.5 58.9Applied (years) 3 4 3 3Yield (kg/10 a) 448 525 480 480 460Relative yield 100 117 107 107 103Materials applied Rice bran 60

KgEMCompost 150 kg

EM Compost 13 kg

Cost of Production Inputs and YieldsKyusei Nature Farming with EM (Farmer’s Groups)

Estimated costs of materials for conventional farming were made by the Agricultural Cooperative Association of Tsuruga City, Fukui Prefecture.(Source: Minami and Higa; 1990)

PSB production in India

(http://www.leofoods.net/en/page2.html

Domestic production of Photosynthetic bacteria(Farmers in Japan and Self experience)

•It can be multiplied in home •One of the cheapest method•0.5 kg crude sugar•0.5 kg of fish head•0.3 L of PSB culture (or collect from pond sides, red colored soil)•15 L of water•Keep it in transparent plastic/glass jar for one month until color turns red

Application•Apply @ 50 liters/1000 sq. m in the paddy field•Live stock @ 0.02 liter/liter of water

•Japanese farmer used in the paddy field •Result encouraging•“Hinohikari” usually produced 120-140 grains/spikelet •With PSB 180-200 grains/spikelet•Grass hopper attacked other field, his rice field was not affected.•Poultry manure doesn’t produce bad odor •Egg size increased•Chickens are active and healthy

Survey in Japan

Conclusion•Green revolution commodity centered•Environment deteriorated by chemical fertilizers•Solar energy is cheap, •CO₂ reduced, bacteria increases photosynthetic rate of plants •Photosynthetic bacteria can be alternative for chemical fertilizers for sustainable rice production and also to combat global warming