it's nice that you know how to google buzzwords but do you actually read the articles you're posting?

Any pH will adjust over time towards the mean, that's nothing new! These results only support our fact that you can use pine needles for an initial acidic infusion when you're amending your shrubs (tested pH levels of below 7 and most in the low 6's and 5's are acidic regardless of how you look at it). As with any amendment, an on-going program has to be developed. If you go to Home Depot and buy your typical urea fertilizers you will be leaching nutrients all over the place. You guys aren't actually winning this debate. It's pretty funny.

My first test consisted of green needles, pulled fresh from the tree. As in all of the needle and soil tests, the needles were placed in a non-reactive container and mixed with an appropriate volume of distilled water following standard analytical testing guidelines and using a proper and calibrated pH meter (single body electrode using standard buffer solutions). The pH of pure distilled water in the container was 6.4. After adding the needles for 10 minutes of soak time, the pH of the green needles was 6.3. To simulate rain water flushing to determine the pH of the leachate of the needles, the needles were allowed to soak for 24 hours and the resulting pH was 4.5. To further simulate the natural rain and drying cycle, the needles were rinsed and then allowed to dry outside for 7 days. The 24 hour soak test was then repeated and the pH was 5.0. The rinsing, 7 day drying cycle and 24 hour soak test was again repeated, followed by two separate 14 day drying cycles and 24 hour soak tests. The pH results were 5.1, 6.2, and 6.5 respectively. From this round of tests, it is clear that the fresh green needles leachate was initially acidic at 4.5, but following several simulations of rain and drying cycles over a few weeks time, the solution (the terms leachate and solution are used interchangeably here) was at the equivalent of rainwater pH. Over a period of 46 days, the needles were no longer acidic, with the pH being that of distilled water.

The second test consisted of freshly fallen needles, the type that would normally be gathered and used as mulch. After 20 minutes of soak time, the pH of the pine straw (the terms pine needles and pine straw can and are used interchangeably here) was 6.6. As with the green needle testing, this test series consisted of an initial 24 hour soak test which was then followed by a 7 day drying cycle, 24 hour soak test, and then two 14 day drying cycles and 24 hour soak tests. The pH results of this series of tests were 5.1, 4.9, 6.0, and 6.0 respectively. In about three weeks the acidity of freshly fallen pine straw was reduced to that of rain water. After 38 days, the pH was increased to 6.0. Following the pattern of the green needle tests the pH likely would reach that of distilled water within the same time frame.

The third test used a combination of whole and broken needles that were bagged and kept dry and out of sunlight since their collection over a span of approximately six months to one year prior to the test. After 30 minutes of soak time, the pH of the pine straw was 5.8. This test was followed by an initial 24 hour soak test resulting in a pH of 4.7. Since the 24 hour soak test result was within the range expected based on previous tests, a 7 day soak test was introduced at this point to look for evidence that longer rain saturation simulation cycles might raise pH at a rate quicker than shorter rain simulation cycles. With the result after 7 days being 5.3, the leaching rate appears to generally follow the same rate of the previous tests that utilized shorter soak and longer drying cycles.

For my fourth test, I utilized decomposed pieces of needles that were approximately 3 months to 2 years old. These pieces were taken from the garden and at the bottom of a five to six inch deep pine straw mulch layer. This mulch has been continually added to, with the top layer being placed there as recently as 3 months ago, and the bottom as long as two years ago. The primary intent of this test was to determine if downward leaching impacted lower levels of mulch. After 30 minutes of soak time, the pH of the pine straw was 4.9. This test was followed by an initial 24 hour soak test resulting in a pH of 4.9 and then a 7 day soak test, after which, the pH was raised to 5.6. These results initially suggest that downward leaching may occur, but longer saturation reduced the pH of the leachate quickly and to that of rain water.