We used corn as experimental plant and harvested until maturity (one cropping only). The area usually used inorganic fertilizer in crop production/experiment. The soil has low N/OM. This was conducted during wet season in Philippine condition.
Biochar had greater adsorption properties for cation through surface oxidation, therefore, many nutrients may be unavailable to plants at higher concentration application. It has also been found that foliage N concentration decreased with more biochar application. It also increased mean annual temperature and reduces the amount of CO2 emission. Moreover, it will be very expensive.
Do some foliar analysis to find out what nutrient was deficient. Biochar is alkaline and depending on the source can have a considerable lime equivalent. What lime equivalent has the char you used? What was the effect on soil pH? What is in the biochar?
Dear Ace Agustin,
Biochar addition significantly increased soil pH but pH value was generally lower during the second growth period probably due to leaching of base cations. Biochar had greater adsorption properties for cation through surface oxidation, therefore, many nutrients may be unavailable to plants at higher concentration application Biochar addition did not reduce ammonium, nitrate, and phosphate leaching during the experiment but it reduced nitrification. Biochar is alkaline and depending on the source can have a considerable lime equivalent.The overall plant growth and soil fertility decreased in the order compost > biochar + compost > mineral fertilizer + biochar > mineral fertilizer > control. Further experiments should optimize biochar–organic fertilizer systems. It is claimed that the addition of biochar to soil improves C sequestration, soil fertility and plant growth, especially when combined with organic fertilizers such as compost.
Article Effects of biochar compared to organic and inorganic fertili...
Article Short-term effect of biochar and compost on soil fertility a...
Article No Effect Level of Co-Composted Biochar on Plant Growth and ...
Thank you so much for the information!
So, either undergoing decomposition process or not (as biochar remains for longer time in the soil), biochar holds nutrients which become unavailable to plants. During decomposition process, available nutrients can be used by microorganism (immobilization); whereas under undecomposed form, it adsorbs cations.
Based on published papers, application of biochar increases the C/N ratio. According to literatures, high C/N ratio means slower decomposition process or higher competition for N between plants and microorganisms. Thus, as long as the biochar is not fully decomposed or mineralized, it will hold nutrients (N) making unavailable for the plants?
interesting discussion . There is every possibility , that FUE will improve , combining small amount of biochar with inorganic fertilizers , since former will act as physical amendment having exceptionally high specific area and high residence time of carbon( 50-60 years) -associated with biochar , collectively triggering improved water transmission properties and microbial communities development...
Dear Ace,
You are raising a host of new issues by suggesting that the material my not have been completely charred. In addition to my other questions I now add: how hot was it and for how long?
You definitely need measurements to remove some of the conjecture, Paul.
The direction of entire discussion will change , considering the fact , whether or not , you tested with mature biochar ..? Please keep in mind , the biochars have that form of carbon, the residence time can last for 50-60 years , even , may be more while comparing with any other carbon form..
To Sir Paul, unfortunately we have limited analysis in this experiment due to limited resources.
Added information:
We used rice hull biochar using simple type of carbonizer (open type). Three weeks after pyrolisis, we applied it to the soil 2 days before sowing.
The result is supplementation of 1.33 t ha-1 rice hull biochar to 150-60-30 kg NPK ha-1 had higher kernel yield than supplementation of 3-6 t ha-1 of rice hull biochar.
Interesting discussion on low rate of biochar application with fertilizer Ver. high rate of biochar application.Corn crop needs good input of nutrients especially N irrespective of improvement in soil physical properties.Also biochar may not facilitie mineralization of soil organic nitrogen as C:N ratio of the soil is high/ wide. Biochar it self can undergo negligible decomposition and mineralization.So the nutrients supply is main limitation in this study which can not be provided by high rate of biochar application.So low rate of biochar plus fertilizer gave high yield of corn.
I think , application of small doses of biochar ( usually have alkaline soil pH) has strong implications on changes in soil pH ( Here i feel , Ace , your soil will be acidic in nature) , thereby , creating a better soil environment plant nutrition...
There have been reports on biochar induced priming effects- positive or negative on soil carbon mineralization .Added nitrogen with biochar can further effect the carbon mineralization in soil low in nitrogen.So in the present study the fertilizer N applied with low rate of biochar application might have facilitated carbon mineralization from soil organic matter providing some soil N through organic N mineralization.The following reference may be consulted.The paper also provides some interesting information on microbial communities alterations with N addition.
Response of biochar induced carbon mineralization priming effects to additional nitrogen in Sandy loam soil. Lu,W. and Zhang,H. Applied Soil Ecology 96:165-171 2015.
Ace, when you say high and low doses what exactly do you mean? It is relative. High yield does not come from biochar alone. It dependent on the type of soil and it's fertility, the amount of water applied, and probably the crop grown. I think it will be important if you give specific figures in terms of the amount of biochar applied, soil type, amount of fertilizer and water applied. This will aid in giving a good answer to your question. I have also read and done some experiments where 'high' doses of biochar promotes high yield.
"Higher" amounts of biochar might fix nitrogen that is not available to teh crops, thus reducing yield potential in the short term compared to "low" amounts of biochar.
Interesting discussion. and if any have papers for apply biochar in hydroponics please uploaded.
- Badges
- Science topic
- Similar topics
- Agricultural Science
- Agronomy