Organic rice-prawn aquaculture (#journal)

Organic rice–prawn farming yields 20% higher revenues

Organic farming of rice and giant river prawns in rotational crops was tested in the waterlogged paddy fields of Kuttanad, Kerala as part of the Indian Organic Aquaculture Project. Rice was cultivated during November to February, followed by a crop of freshwater prawns in the same field from March to September. Farming rice organically reduced yields by 23 %. However, the organic prawn crop yield was 10 % higher than the yield of the conventional system, so although organic rice farming realized lower returns than conventional, its combination with organic prawn farming enhanced net revenue by 20 % over conventional rice/conventional prawn production.

Winter legume rotation improves rice yield (#journal)

Winter legumes in rice crop rotations reduces nitrogen loss, and improves rice yield and soil nitrogen supply

Intensive irrigated rice-wheat crop systems have caused serious soil depletion and nitrogen loss in  China. A possible solution is the incorporation of legumes in rice, but little is known on the impact of legumes on rotation, soil fertility, and nitrogen loss. This study considered the effect of five rice-based rotations on soil nitrogen, rice yield, and runoff loss. Results show that replacing 9.5–21.4 % of nitrogen fertilizer by rape, vetch or bean residues maintained rice yields, and using legumes as a winter crop in rice-bean and rice-vetch combinations increased rice grain yield 5 % while decreasing nitrogen runoff 30–60 %.

Low input maize for biofuel (#journal)

Efficient biofuel production from traditional maize under low input

Traditional crop varieties are adapted to low inputs of fertilizers, pesticides, and water. The authors tested the suitability of traditional maize varieties as solid biofuel, cultivating traditional maize varieties without pesticides and irrigation and then measuring the heating value, the ash content, and the elemental composition. Results show that plants harvested at maturity, 150 days after sowing, have about 10 % more biomass and 20–30 % less ash, N, K, and Cl than plants harvested 115 days after sowing. Traditional maize varieties can produce an energy of 15–23 · 10⁴ MJ/ha. These findings demonstrate that traditional maize cultivation can be optimized to increase the efficiency of biomass production and to reduce the environmental impact.

Intro to system science and permaculture (online)

Thinking Systematically: Achieving Sustainable Systems

A simple introduction to systems science and its links to permaculture:

• Systems science provides a means of analyzing and understanding complex processes based on a few basic principles
• Complex systems behave in complex ways and may change over time
• When problems emerge there is an underlying positive feedback loop that may not be evident
• Such problems cannot be solved using linear causality thinking
• True sustainability involves whole systems thinking and design
• Permaculture is the application of systems thinking to the design of living arrangements

Shelter belt design guide (online)

The Principles of Using Woods for Shelter

This Information Note describes the physical principles that determine the impact of woodlands on shelter provision. The importance of the woodland height, porosity, width, length, orientation and shape on the area and level of shelter are discussed. Three generic shelter wood types are identified (‘windshield’, ‘windbreak’ and ‘hybrid’) together with their most
appropriate applications. The Note points to the crucial need to understand the reasons for creating shelter in order to determine the most effective design.

An apology... and 100 references in one

The biggest permaculture literature review to date, revisited

This month I have been crazily busy with a number of funding deadlines and other projects, plus taking some holiday, with the result that The Digest has been badly neglected. Sincere apologies. It will be back on track in June. In the meantime, for those of you who feel you are missing out on your permaculture reading, here is a second mention of the biggest permaculture literature review yet undertaken, initially featured on The Digest last November. This link will take you to the full text of the article, which should keep you occupied for at least a couple of hours!

Best wishes to all Digest readers,

Chris

Uk agriculture facts website (online)

UK Agriculture 

This web site about agriculture and farming was established in 1999 in an attempt to help widen understanding about the role of agriculture in the countryside. The website attempts to provide an easy to read, visual approach to the chronology of agricultural systems and the relationship between food and farming. It is also committed to preserving the countryside and improving its biodiversity.