The attached pdf will guide you to fix the application rate and frequency of application of Bio-char. Bio-char application to soil may have direct or indirect negative effect on beneficial microorganisms specially arbuscular mycorrhizal fungi in soil due to changes in pH, water availability, toxic mineral, organic compounds or decrease in available nutrients due to sorption (Lehmann et al. 2011).

Positive and negative effects of biochar from coconut husks, orange bagasse and pine wood chips on maize (Zea mays L.) growth and nutrition( Article Positive and negative effects of biochar from coconut husks,...

Abstract: Transformation of organic waste into biochar for land application is a relatively new green technology management tool. Land-applied biochars can improve soil quality and plant growth. The aim of our study was to investigate the effects of biochars derived from coconut husk, orange bagasse and pine wood chips at different rates of application (0, 5, 10, 20 and 60 t ha− 1), on the biomass, nitrogen (N) and phosphorus (P) status of maize (Zea mays L) cultivated in a sandy soil, under greenhouse conditions. The treatments were arranged in a completely randomized block design with four replications. The effects of biochar addition on plant dry biomass and nutrition were dependent upon the biochar type and application rate. Soil treated with coconut husk biochar at an equivalent rate of 30 t ha− 1 resulted in a 90% increase in maize biomass and plant N and P concentrations of 0.88 and 0.12%, respectively. Orange bagasse biochar applied at a similar rate had no effect on plant biomass, and resulted in plant N and P concentrations of 0.85 and 0.15%, respectively. Application of pine wood chip biochar to soil did not affect plant biomass or nutrition. Even though soil total N increased with an increasing application rate of orange bagasse biochar, N leaching may not have posed a problem since KCl extractable N decreased. However, the associated increase in soil pH may result in potentially greater N losses over time. Thus, the increase in plant biomass and nutrition indicates the superiority of the coconut husk biochar as soil amendment; yet, the application of orange bagasse biochar needs more investigation.

Other review highlights the negative impact on earthworm population ...PDF enclosed..

Dear Sugumaran,

thanks for your question, which clearly shows that this issue is scarcely communicated. As mentioned biochar properties vary (see various meta-analyses and reviews, e.g. Libra et al . 2011, etc.) and thus their application to soil varying in their properties increases complexity of interactions and induced impacts on for instance plant productivity (see also various reviews and meta-analyses, e.g. Jeffery et al. 2011, Biedermann & Harpole 2012, Crane-Droesch et al. 2013). Especially, Crane-Droesch et al 2013 assessed data deeply and were able to publish mechanistic knowledge, which may answer some of your questions.

Despite that I highly recommend to test at laboratory and field impact of your biochar(s) to assess best application rate and frequency of application. However, your research question may affect designnof your experiments and final recommendations; e.g. plant productivity, C sequestration, soil rehabilitation etc. Thus, I rather recommend to test your biochar(s) than to follow any universal recommendation (e.g. most likely not adapted to your problem).

Best

Nils

Some more interesting PDFs on the topic in discussion...

Investigation and researches has shown that biochar is resistant to biological degradation and it can last for several centuries in soil (that is why it is considered a promising tool for carbon sequestration). The Terra Petra historic sites in Amazon, are from several thousand years old, and are still more fertile than the adjacent native soils. Therefore, I believe that it is not necessary to apply biochar more frequently, like manure. Manure is being applied every 2-3 years. More long term experiments are needed to evaluate the longevity of the beneficial (or negative) effects of biochar in soil. But I think, considering its physical and chemical properties, if applied in the right amounth, it is a one time application for a long time. That long time I can not say how many years, and research and evaluation is needed. Field studies with biochar is alot less than greenhouse and laboratory experiments. Production and application costs are somewhat expensive. But its resistance to degradation and long term staying in soil, makes it a one time cost for farmers.

Best Regards.

Exact quantity varies with cropping intensity,soil type and type of crops.However,few negative effects involve poor efficacy of soil applied herbicides which get adsorbed on biochar content.This adsorption renders lesser efficiency as depending upon adsorption of herbicide molecules,it's availability for sought after effect decrease.Accordingly slightly higher amount of such herbicides may be needed in soils applied with biochar as compared to soils without biochar application.

Dear all,

Thank you for your valuable suggestions and information.

Dear Dr. Anoop Kumar Srivastava & Dr. Farhad Khorsandi

whether biochar can apply to alkaline soil ? if applied soil pH will increase. so biochar is not suitable for the above type of soil.

suggestion please.

Dear Sugumaran

I have done several greenhouse experiments with calcareouse soils and biochar. mostly I have used citrus tree wood biochar. pH raised but not significantly. In one experiment it decreased but not significantly (1, 2 and 4% application rate by weight). Also, EC of soil increased a bit, specially at higher rates. But, in all 4 experiments, they did not affected plant growth and yeilds (corn, sunflower, jatropha, forage maze). In all my experiments 2% application rate was the optimum. 2 of my experiments were under irrigation with saline water actually. Biochar improved growth under saline conditions (low to moderate levels of salinity).

Regards

Very interesting . Bio hat holds promise under variety of soil conditions with varying magnitude of response. ..

Sorry biochar

Dear Dr. A.K.srivastava,

Good morning!

Thank you for sending the review article on The role of biochar and biochar compost in improving soil.....A review. The paper has very good information and also provide wide knowledge on biochar application into soil. So very useful to me.

I would like to thank you once again.

Best Wishes

Sugumaran