I live in an area with high rainfall. How can I maintain and improve the soil fertility without...

the soil leaching nutrients?

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Would mulching with wood chips help?

I done that but you really have to watch your chips types, and if you do all the right things you can grow great tree's in the long run but in the short term its really hard on herbaceous plants as they prefer a bacterial base soil. You'll have fungal chips for a long time and you will have to keep feeding it nutrients to lock up in the short term for a long term release. It's allot i mean allot of carbon and it can sequester a hell of allot of nutrients. So in theiry you got the fertility but you won't have available fertility, I gotta go eat dinner so I didn't expand. But if you do want to deal with allot of mud let's say I've learned allot over the last 3 years of playing the woodchip game. I've made hole swales out of mud and woodchips and I'm starting to see a real mushroom fruiting mania after a year's worth of input's. It grows oh so itty bitty plant's that barely grow, but i'm starting to see the changeover in that situation with a growing worm population, but other places where i've made mistake's i still got untouched woodchips from 3 year's ago.

I can write more if your interested, but I know for tree's with the right woodchip compost I've had 100% transplant success of really old really sick and damaged tree's that also fruited the same year as a late may transplanting.

Why only wood chips? Any mulch will reduce impact of rain and hold nutrients.

I live on an island in British Columbia and it does get high rain fall at times. It is hard to build soil here and it often is leaning a bit toward the acidic side. Over the years I have just used mulch. cardboard and at times of high rainfall during peak winter I will cover my beds with a tarp to minimize soil and nutrient leaching. Of course come spring you need to remove all of these things so the soil can warm up. You could also experiment with winter ground covers to build nutrients and hold your soil intact, this I find is the best method because its little input for a lot of action and output, of course depending on what you plant you will have to turn it over in the spring. Another factor to consider is what type of soil you have, A simple test can determine that( it can be found in the book the soul of soil) once you know this you can help the soil structure along by either building it up with organic matter (you should do anyway) or possible De-compaction of soils high in clay or that have been over grazed or over worked. My teacher gave an example of using a yoU bar digger or fork that can be found at lee valley or you could make one yourself. By simple just moving through the compacted area and just lifting the soil, not turning it, you get more effective drainage and aerobic activity in the soil.

I hope this has helped

It's true, mulch is your friend. Any mulch will help, and currently there's a bit of a wood chip frenzy going around our area due to Paul up there on Chicken Coop Road, right past the casino. Have you seen the film? I thought they played it at the college a few months ago, but you can watch online.

http://backtoedenfilm.com/#movie

It's got a religious message, as Paul is a very spiritual man, but I really enjoyed it even though I don't share his religious views.

Anyway, we're fortunate as we have access to the same material suppliers as he uses. I've spoken with Steve at Lazy J, the source for organic chips and compost, and may try the technique on a small plot this year. That said, even though this is only 15 miles away, he gets about half the rainfall I do. I'll be curious to see how it does with my saturated soil. It is important to keep the chips from mixing with the soil too much, or, as posted above, you get a mushroom farm with a lot of the nutrients tied up for a while.

On a different tack, I've had good luck with straw as mulch during the wet season. Once things dry out a bit though, it's crucial to remove it or the critters will live in there and eat all your veggies.

I've had the most success with row covers and low tunnels. We are just SO wet in the spring, that without some protection it's very difficult to get an early start on most plants.

I have a LOT of wool from shearing last spring sitting in the barn, so I might try that as a ground cover on a plot this spring to see if that helps. You are welcome to some of that if you are interested. Not sure how it works though.

Pond liner is great for catching both rain and nutrients. If you can't beat 'em, join 'em.

Rice paddies have been continuously farmed for hundreds of years in high-rainfall areas with nothing like the nutrient loss associated with other types of grain production. Aside from rice, hard to beat aquaculture for productivity or profitability.

Can you elaborate on how much rainfall and what types of soil (clay, sand)? Is this in a garden? forest? Any slope?

Wood chips will still allow water to pass through so the cardboard idea sounds better to me. But to maintain organic matter, I would continuously mulch with leaves and other more nutritious plant foods. Maintain that humus layer if you can and hopefully losses to leaching will be acceptable. Wood chips alone will not add much to your soil.

I like kame's suggestions of just going with the flow...