Safflowerseed meal. See Cottonseed meal.
Sawdust contains virtually nothing but carbon. In small quantities it is useful to fluff up compost piles and prevent compaction. However this is only true of coarse material like that from sawmills or chain saws. The fine saw dust from carpentry and cabinet work may compact and become airless. See Paper for a discussion of lowering the fertilizing value of compost with high C/N materials.
Seaweed when freshly gathered is an extraordinary material for the compost pile. Like most living things from the ocean seaweeds are rich in all of the trace minerals and contain significant amounts of the major nutrients, especially potassium, with lesser amounts of phosphorus and nitrogen. Seaweeds enrich the heap, decompose very rapidly, and assist other materials to break down. Though heavy and often awkward to gather and haul, if they are available, seaweeds should not be permitted to go to waste.
Those with unlimited money may use sprinklings of kelp meal in the compost pile to get a similar effect. However, kelp meal may be more economically used as part of a complete organic fertilizer mixture that is worked into soil.
Shrub and tree prunings are difficult materials to compost unless you have a shredder/chipper. Even after being incorporated into one hot compost heap after another, half-inch diameter twigs may take several years to fully decompose. And turning a heap containing long branches can be very difficult. But buying power equipment just to grind a few cart loads of hedge and tree prunings each year may not be economical. My suggestion is to neatly tie any stick larger than your little finger into tight bundles about one foot in diameter and about 16 inches long and then burn these "faggots" in the fireplace or wood stove. This will be less work in the long run.
Soil is an often overlooked but critically important part of the compost pile. Least of its numerous benefits, soil contains infinitudes of microorganisms that help start out decomposition. Many compostable materials come with bits of soil already attached and few are sterile in themselves. But extra soil ensures that there will initially be a sufficient number and variety of these valuable organisms. Soil also contains insoluble minerals that are made soluble by biological activity. Some of these minerals may be in short supply in the organic matter itself and their addition may improve the health and vigor of the whole decomposition ecology. A generous addition of rock dust may do this even better.
Most important, soil contains nitrification microorganisms that readily convert ammonia gas to nitrates, and clay that will catch and temporarily hold ammonia. Nitrifying bacteria do not live outside of soil. Finally, a several inch thick layer of soil capping the heap serves as an extra insulator, holding in heat, raising the core temperature and helping seal in moisture. Making a compost heap as much as 10 percent soil by dry weight is the right target
Try thinking of soil somewhat like the moderators in an atomic reactor, controlling the reaction by trapping neutrons. Soil won't change the C/N of a heap but not being subject to significant breakdown it will slightly lower the maximum temperature of decomposition; while trapping ammonia emissions; and creating better conditions for nitrogen fixing bacteria to improve the C/N as the heap cools and ripens.
