Application of intensive gardening methods to rice fields increases grain yields substantially.
RICE RESENTS TRANSPLANTING
Bare Root Transplants Grown in Manure Compost (40 days from seeding): 3,122 pounds per acre
2-Inch Manure Cubes: 5,303 pounds per acre
5-Ounce Manure Pots: 6,089 pounds per acre
Direct Seeded Sprouted Rice: 7,620 pounds per acre
Transplant shock reduces yields. Pots are better than cubes for preventing root injury. Transplant seedlings directly first root shows on pot or cube. There is no advantage to delayed planting. Set transplants as soon as practical. Every day lost lowers grain yield. For best results plant pre-sprouted seeds.
RICE DISLIKES FLOODING
Paddy Rice (continuous flooding 8 inches deep): 2,884 pounds per acre
Upland Rice (sprinkler irrigated 28 inches): 4,400 pounds per acre
Rice tolerates flooding but does not thrive. For best yields keep fields moist but not wet. Roots need oxygen to absorb water and nutrients.
CULTIVATION HARMS RICE
Machine Cultivated 4 Times (every 14 days): 2,911 pounds per acre
Hand Weeded 4 Times (every 14 days): 3,460 pounds per acre
56-Day Flood 8 Inches Deep: 3,885 pounds per acre
Flame Weeded 4 Times (every 14 days): 4,336 pounds per acre
Dutch White Clover Living Mulch: 4,532 pounds per acre
Burlap Mulch 2 Bags = 4 Layers Thick: 5,617 pounds per acre
Chopped Weed Mulch 6 Inches Deep: 6,503 pounds per acre
Velvet Bean Mulch-In-Place: 6,924 pounds per acre
Any practice that disturbs soil ecology lowers crop yields. For best results do not plow, disk, harrow, or cultivate fields. Do not interfere with natural biological processes. Try to mimic nature whenever practical.
CROWDING LOWERS RICE YIELD
1 Pre-Sprouted Seed Per Hill: 6,887 pounds per acre
1 Transplant Per Hill: 4,143 pounds per acre
3 Transplants Per Hill: 3,681 pounds per acre
5 Transplants Per Hill: 2,343 pounds per acre
10 Transplants Per Hill: 2,616 pounds per acre
15 Transplants Per Hill: 2,569 pounds per acre
(12-inch equidistant spacing. 208 rows x 208 plants per row = 43,264 plants per acre. 40-day transplants from seeding).
Equidistant spacing increases crop yields by reducing plant competition for light and nutrients. Direct seeded crops usually outperform transplants. Transplant shock is not always immediately apparent; crops can be retarded 2 to 3 weeks which lowers yields.
IRRIGATION BOOSTS GRAIN YIELD
20 Inches Rainfall: 1,298 pounds per acre
Continuous Flooding 1 Inch Deep: 2,559 pounds per acre
20 Inches Rainfall + 8 Inches Irrigation at Grain Filling: 3,003 pounds per acre
Monsoon Rice (Exceeding 28 Inches without Flooding): 3,854 pounds per acre
Ridge & Furrow Irrigation (28 inches): 4,235 pounds per acre
Sheet Irrigation (28 inches) = No Standing Water: 4,870 pounds per acre
Sprinkler Irrigation (28 inches): 5,736 pounds per acre
Drip Irrigation (28 inches): 6,480 pounds per acre
Most agricultural soils do not have enough oxygen for optimum crop growth. Flooded fields yield poorly.
FERTILIZER INCREASES RICE YIELD
No Fertilizer (Rice After Fallow): 3,014 pounds per acre
Supplemental Phosphorus Only (40 pounds per acre): 3,949 pounds per acre
5-10-5 Broadcast (1 Ton Per Acre = 100 Pounds Nitrogen): 4,642 pounds per acre
Velvet Bean Mulch-In-Place (98 Pounds Nitrogen Per Acre): 5,220 pounds per acre
Composted Cow Manure (8 Tons Per Acre = 104 Pounds Nitrogen): 5,833 pounds per acre
Manure Lagoon Water (0.75 Acre-Inch = 20,000 Gallons = 100 Lb Nitrogen / Acre): 6,750 pounds per acre
Small amounts of nutrients can double yields. Prefer biological fertilizers whenever practical.
RICE PREFERS DEEP SOILS
4 Inches of Topsoil over Granite: 1,338 pounds per acre
8 Inches of Topsoil over Granite: 1,734 pounds per acre
12 Inches of Topsoil over Granite: 2,223 pounds per acre
18-Inch Raised Bed: 3,446 pounds per acre
24-Inch Raised Bed: 4,580 pounds per acre
36-Inch Terrace: 4,965 pounds per acre
Crop yield is directly related to soil volume. More roots = more water and nutrients = bigger harvests. Manage fields to increase soil depth and eliminate compaction. Rule-of-Thumb: 5% yield loss for every 1-inch decrease in topsoil depth. 2.25% yield loss for every 1-inch decrease in subsoil depth. This rule applies to most seed crops.
SEED INOCULATION RAISES GRAIN YIELDS
Pre-Sprouted Upland Rice without Beneficial Microbes: 2,622 pounds per acre
Upland Rice Seed Soaked 24 Hours in Fresh Cow Manure Tea (1 dung : 1 water by weight): 3,361 pounds per acre. Use FRESH manure only. Do not use dried or composted dung.
Upland Rice Seed Soaked 24 Hours in Compost Tea (1 compost : 1 water by weight): 3,638 pounds per acre. Use only low temperature, aerobic, fungal dominant compost.
Rice grows better with symbiotic fungi and bacteria. Fungi provide water and minerals to rice. Bacteria fix nitrogen. Active soil biology replaces synthetic chemicals.
SOIL AERATION INCREASES RICE YIELD
16 Inches Topsoil: 2,809 pounds per acre
Subsoil Tillage 16 Inches Deep (0.75-inch wide slit every foot): 3,711 pounds per acre
16 Inches Potting Soil (1 topsoil + 1 coarse sand + 1 peat = 3 parts by volume): 4,261 pounds per acre
16 Inches Topsoil over 4-Inch Diameter Forced Air Ducts Every 2 Feet Apart (220 cubic feet per minute): 5,369 pounds per acre
16 Inches Composted Hardwood Bark: 6,546 pounds per acre
For highest yields manage fields to increase soil porosity. Healthy soils need to breathe. Roots need air to absorb water and nutrients. More oxygen = bigger harvests.
HISTORICAL NOTE: Yield data come from numerous unrelated experiments conducted at many diverse sites over 5 decades, 1930 to 1980. Results are not definitive (absolute) but rather suggestive. The trends are more important than the numbers. For example: Flooded rice generally yields less than sheet irrigated rice (alternate wetting and drying) which usually produces lower yields than sprinkler irrigated rice. These results typically hold true regardless of variety, cultural methods, or environmental conditions. Experimental data vary but the underlying principle does not: Soil aeration increases grain yields. More oxygen = more rice.
This article was written before development of the modern System of Intensive Rice Cultivation. Consequently, the importance of transplanting 10 to 12-day old seedlings was unknown to the Author. 2-leaf transplants develop many tillers which greatly increase rice yields. Equidistant spacing of young transplants is the foundation of intensive rice agronomy.
DEDICATION: This article is dedicated to Father Henri de Laulanie de Sainte-Croix, S.J., who taught me that humility precedes learning. This is not an easy lesson to master. Friar Laulanie (1920 – 1995) was the inventor of intensive rice cultivation = Systeme de Riziculture Intensive (SRI). I had the privilege of working with Friar Laulanie while he developed his new rice agronomy. My interest was in mechanized plantation agriculture while Father Laulanie was the champion of small field subsistence farmers. Consequently, we often approached problems from entirely different directions. I miss our lively correspondence and, especially, our friendly debates, most of which I lost. There is nothing quite like the experience of being steam rolled by the relentless logic of a Jesuit mind.
RELATED PUBLICATIONS: Chemical to Organic Rice Conversion Trials, Trino, Italy 2014 – 2019; Garden Rice Trials, Paia, Hawaii 1924 – 2020; Intensive Rice Culture Primer; Paddy Rice Agronomy Trials, Trino, Italy 1853 – 1910; Ratoon Rice Trials, Paia, Hawaii 1877 – 1924; Rice and Gram Polyculture, Pondicherry, India 1763 – 1865; Rice Polder Trial, Butler, Pennsylvania 1972; Rice Rotation Trial, Puerto Limon, Costa Rica 1950 – 1973; Termite Mound Effects on Upland Rice Yields, Koh Kong, Cambodia 1955.
OTHER ARTICLES OF INTEREST: Wheat Agronomy Trials 2016 – 2020; Red Fife Winter Wheat Trials 1990 – 2009; Stomp Seeded Winter Barley Trials 2008 – 2017; Yield of Small Grains Surface Seeded into Standing Dutch White Clover; Maize and Kidney Bean Polyculture; No-Till Nankeen Cotton in Mulch-In-Place Palmer Amaranth; Growth Stimulation of Pea Nodules by Companion Oats; Oat, Pea, and Turnip Polyculture Trial; Hand Cultivated Maize versus Mexican Sunflower Mulch-In-Place; Upland versus Wadi Barley Cultivation in Morocco; Yield of Forest Rye Grown on Quarry Sand Terraces; Maize Polyculture Trial 2007 – 2016.
WOULD YOU LIKE TO KNOW MORE? For more information on biological agriculture and intensive grain farming please visit: http://www.worldagriculturesolutions.com — or — mail your questions to: Eric Koperek, Editor, World Agriculture Solutions, 413 Cedar Drive, Moon Township, Pennsylvania 15108 United States of America — or — send an e-mail to: worldagriculturesolutions@gmail.com.
Cornell University hosts a comprehensive SRI website at: http://www.sririce.org. E-Mail Address: sririce@cornell.edu.
The original SRI papers by Friar Laulanie are available both online and in the scientific journal Tropicultura: Technical Presentation of the System of Rice Intensification, Based on Katayama’s Tillering Model. Henri de Laulanie. 1993 Tropicultura 13 : 1. Intensive Rice Farming in Madagascar. Henri de Laulanie. 2011 Tropicultura 29 : 3 (183 – 198).
For more information on French Intensive Gardening read this classic work: Manuel Pratique de la Culture Maraichere de Paris. J.G. Moreau. 1845 Alex Richards, Paris. Reprinted in 2010 by Nabu Press. International Standard Book Number (ISBN): 978 114 387 662 2.
ABOUT THE AUTHOR: Mr. Koperek is a plant breeder who farms in Pennsylvania during Summer and Florida over Winter. (Growing 2 generations yearly speeds development of new crop varieties).
INDEX TERMS: 5-10-5 (chemical fertilizer); Aerobic Compost; African Rice; Alternate Wetting and Drying (irrigation); Asian Rice; Beneficial Bacteria; Beneficial Microbes; Burlap Mulch; California Rice Farming; Compost Tea; Composted Hardwood Bark; Cover Crops; Cow Manure Compost; Direct Seeding; Drip Irrigation; Equidistant Spacing; Flame Weeding; Flood Irrigation; French Intensive Gardening; Fungal Dominant Compost; Hand Weeding; Henri de Laulanie (agronomist); Hills (for planting); Indian Rice; Intensive Rice Agronomy; Intensive Rice Culture; Intensive Rice Farming; Intensive Rice Growing; Japanese Rice; Lowland Rice; Low Temperature Compost; Manure Cubes; Manure Lagoon Water; Manure Pots; Manure Tea; Monsoon Rice; Mucuna utilis; Mulching; Mulch-In-Place; Nitrogen Fixing Bacteria; Organic Fertilizers; Organic Rice Farming; Oriental Rice; Oryza glaberrima; Oryza sativa indica; Oryza sativa japonica; Paddy Rice Cultivation; Phosphorus (fertilizer); Plant Density; Pre-Sprouting Seeds; Rice Tillering; Ridge and Furrow Irrigation; Seed Inoculation; Seed Priming; Sheet Irrigation; Sistema Intensivo de Cultivo Arrocero; Soil Aeration; Soil Depth; Soil Porosity; Sprinkler Irrigation; Subsoil Tillage; Symbiotic Fungi; System of Rice Intensification; Systeme de Riziculture Intensive; Transplanting; Upland Rice; Velvet Bean; Weed Control; West African Rice.
ORIGINAL PUBLICATION DATE: November 1981, Lime House, Dominica
UPDATE: July 2023, Homestead, Florida