Job offersmore »

Tweeting Growers

Top 5 - yesterday

  • No news has been published yesterday.

Top 5 - last week

Top 5 - last month

Exchange ratesmore »

Effect of plant species, fertilizer on soilless root substrate pH

The objective of this study was to determine how plant species, fertilizer potential acidity/basicity rating (PABR), and fertilizer concentration affect root substrate pH. Three experiments were conducted.

In the first experiment, 13 herbaceous species were grown in a root substrate of three sphagnum peatmoss: one perlite (v/v) with deionized water and a neutral fertilizer (NF) with a PABR of 0 for 78 days to determine species relationships to substrate pH. The decrease in substrate pH ranged from 0.14 to 2.45 units, depending on species.

In the second experiment, four of the 13 species from the previous trial representing the range of pH suppression were grown under similar growth conditions as the first experiment for 70 days. Substrate pH was lowered in the range of 0.47 to 2.72 units.

In the third experiment, three fertilizers with PABRs of 150 kg·t−1 CaCO3 equivalent alkalinity, 0 neutral, and 193 kg·t−1 CaCO3 equivalent acidity were applied in a factorial design at 100 and 200 mg·L−1 N at each irrigation to kalanchoe (the species with the greatest pH suppression from the previous experiments) for 56 days.

When applied at the lower fertilizer rate (100 mg·L−1 N), the PABRs resulted in the final substrate pH levels of 4.68, 5.60, and 6.11 for the acidic fertilizer (AF), NF, and basic fertilizer (BF), respectively. At the high fertilizer rate (200 mg·L−1 N), substrate pH declined continuously to 3.97, 4.03, and 4.92 for the AF, NF, and BF, respectively.

Expression of PABR depended on the balance between the abiotic (chemical) effect of the fertilizers vs. the biotic (physiological) effects of the fertilizers on microbes and plants. The PABR was best expressed when the fertilizer supply was just adequate or lower indicating a closer connection to the biotic effect.

Access the full study at HortScience

Publication date: 1/6/2017



Other news in this sector:

6/12/2018 US (WA): Turning urban wood waste into biochar
6/11/2018 Australian strawberry grower increases yield with rockwool
6/8/2018 Loco about Coco
6/4/2018 Jiffy Products Sri Lanka successfully EU Organic certified
5/30/2018 Poland: New carbon substrate from organic raw material
5/23/2018 "Reducing labour costs and improving crop growth in soft fruit"
5/22/2018 Strawberry growers in Spain move out of soil
5/16/2018 Oasis starts offering Rootcubes retail packs
5/4/2018 "Greatest gains expected after summer solstice"
4/26/2018 Development of substrates for multilayer cultivation in high-tech phytotrons
3/29/2018 US: 100th independent trial of soil health product on bell peppers
3/28/2018 US (NY): Cornell student to develop weed-free growth media
3/15/2018 King Willem-Alexander opens new compost factory for mushroom substrates
3/1/2018 Benefits of maintaining the optimum substrate oxygen level
2/13/2018 Humic acid coloured perlite for higher consumer acceptance
2/12/2018 Biochar could replace unsustainable peat moss in greenhouse industry
2/12/2018 Peat moss: A sustainable component of growing media
2/2/2018 UK wants to get rid of UK peat in commercial horticulture
1/9/2018 US (MI): Managing substrate pH of soilless substrates
12/14/2017 New flat coir grow bags in four specialty blends