An Advancment in Nitrogen Fixation by Endophyte

Now a days, a lot of new technologies have been implied to boost up N availability such as use of N fixing microorganisms or use of organic acids. But little attention has been given to the use of endophytes to enhance the N availability and nitrogen losses. Endophytes are micro-organisms that live within the tissues of a plant, without causing symptoms of disease. Endophytes can be used to develop bio-fertilizer that releases nitrogen slowly. Therefore, now researchers are focusing on the use of endophytic bacterial impregnation to prolong the availability of N in soil to replenish the pool of N to meet the plant requirements.

Controlled Release Fertilizers:  

Controlled-release fertilizers are being developed to improve nutrient use efficiency while reducing environmental hazards. It has also been reported that greater fruit yield was obtained using controlled-release fertilizers compared with water soluble fertilizers. These types of fertilizers can provide many benefits to agriculture, such as higher fertilizer use efficiency, reduced nutrient losses via fixation, leaching and denitrification and reduction of soil chemical processes that decrease the availability of nutrients. Therefore impregnation of commercial urea with endophytic bacteria could be effective to pro log the availability of nitrogen to plants in soil.

Experiments at Endophytic Efficiency:  

To investigate the efficiency of endophytic bacterial impregnated urea, pot trial was conducted at wire house of Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad. Two bacterial strains FD17 and PSJN were impregnated on urea. There were 8 treatments with 3 replications of each. The data regarding growth, yield and chemical parameters was obtained and analyzed statistically. Obtaining best results of T8 and preceding T5, it was concluded that endophytic bacterial impregnated urea showed maximum growth and yield as compared to other treatments. It was inferred that endophytes are helpful in prevention of nitrogen losses and enhance nitrogen use efficiency of plants and soil.

Results of study:  

Results of study indicated that wheat crop responded positively to the application of endophytic bacterial impregnated urea as compared to uncoated urea and control (no NPK was applied). Maximum plant heights were obtained from T5 (NPK + Seed inoculated both strains FD17 and PSJN) and T8 (Urea impregnated with strains FD17 and PSJN) Bacterial strain FD17 and PSJN coating on urea were found to be superior in most of the yield and growth parameters. Treatment (T8) having endophytic bacterial impregnated urea concentration improved the N concentration in shoot (2.61%) as compared to uncoated urea (T2) in which N concentration of shoot.  Application of endophytic bacterial impregnated urea improved the growth, yield and nitrogen use efficiency of crop. The maximum chlorophyll content was recorded in plants which received treatment T8 (PK + Urea impregnated with strains FD17 and PSJN) following T5 (NPK + Seed inoculated both strains FD17 and PSJN) and T7 (NPK + Seed inoculated both strains FD17 and PSJN) and these treatments produced 48, 47 and 45 spad value, respectively chlorophyll contents. Because endophytic bacterial impregnated urea converted it into more available form for a longer period as it slowed down the release of N. In T8 where endophytic bacterial impregnated urea with 100% recommended rate showed the highest percentage of nitrogen (as compare to uncoated urea) in grains. Overall experiment results suggested that coated urea as N source significantly increased most of the growth and yield parameters. Obtaining best results of T8 and preceding T5, it was concluded that endophytic bacterial impregnated urea showed maximum growth and yield as compared to other treatments. Endophytic bacterial impregnated urea has following benefits over un-impregnated urea:

•  Increased nutrients uptake and hence their use efficiency.
•  Performed better than uncoated N fertilizers.
•  Reduction in losses of N that resulted in more availability of N in soil.
•  Released the nutrients slowly and made it available throughout the growth period.
•  Reduced the fertilizer application rate due to higher uptake compared to uncoated urea.

CONCLUSION:

Keeping in view the above discussion, it can be concluded that use of slow release fertilizers more specifically endophytic bacterial coated fertilizers has significant effect on the growth and yield of crops and vegetables by controlling nutrient release rate and nutrient use efficiency.
By: Shoaib Aslam

Coated Fertilizers And Agriculture

Many technologies have been implied to boost up phosphorus (P) solubility such as use of P solubilizing microorganisms or use of organic acids. But little attention has been given to the use of organic polymer to enhance the P availability. Organic polymer can be used to develop phosphatic fertilizer that releases phosphorus (P) slowly. The organic polymer (complex organic compounds) absorbs water more efficiently and keeps the P in available form. The organic polymer can hold water many times of its weight and prolong the availability of P to plant roots. Phosphatic fertilizers with organic polymers are usually termed as slow releasing fertilizer because these fertilizers provide P to plants at slower rate but regularly. Therefore, now researchers are focusing on the use of polymer for DAP (diammonium phosphate) coating to prolong the availability of P in soil to replenish the pool of P to meet the plant requirements. Controlled-release fertilizers are being developed to improve nutrient use efficiency while reducing environmental hazards.

Controlled-Release Fertilizers:

It has also been reported that greater fruit yield was obtained using controlled-release fertilizers compared with water soluble fertilizers. This type of fertilizer can provide many benefits to agriculture, such as higher fertilizer use efficiency, reduced nutrient losses via fixation, leaching and denitrification and reduction of soil chemical processes that decrease the availability of nutrients, such as the fixation of P. Therefore coating of commercial DAP with organic polymer could be effective to prolog the availability of phosphorus to plants in soil.

Experiment at Coated DAP:  

To investigate the efficiency of polymer coated DAP, field trial was conducted at research area of Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad. Different rates of organic polymer coated DAP (100, 75 and 50%) were applied in comparison with uncoated DAP. Data regarding plant height, number of tillers m-2, 1000-grain weight, grain yield and total grain yield were collected. Results of the study obtained after statistical analysis are summarized as under.

Results for Coated DAP:

Results of study indicated that wheat crop responded positively to the application of polymer coated DAP as compared to uncoated DAP and control (no P was applied). Application of polymer coated DAP improved the growth, yield and nutritional aspects of crop. 100% polymer coated DAP was found to be superior in most of the yield and growth parameters. Because polymer coating on DAP converted it into more available form for a longer period as it slowed down the release of P. Overall experiment results suggested that polymer coated DAP as P source significantly increased most of the growth and yield parameters. Polymer coated DAP has following benefits over uncoated DAP.

Polymer coated DAP: 

• Increased nutrients uptake and hence their use efficiency.
• Performed better than uncoated DAP.
• Reduction in soil fixation of P that resulted in more availability of P in soil.
• Released the nutrients slowly and made it available throughout the growth period.
• Reduced the fertilizer application rate due to higher uptake compared to uncoated.

References:

1. Murphy, L and L. Sanders. 2007. Improving N and P efficiency with polymer technology.         Ind. CCA Conf. Pro. 1-13.
2. NFDC. 1997. Fertilizer Recommendations for Crops. pp. 33-46. In. “Fertilizer Recommendations in Pakistan (a pocket guide for extension workers)”. National Fertilizer Development Center, Islamabad, Pakistan

By : Shoaib Aslam

Use of Biochar to Combat Climate Change

Biochar is a climate saving soil that holds carbon, boost security of food, discourage deforestation and increase soil biodiversity. The procedure makes a highly porous, fine-grained charcoal that helps soils retain water and nutrients. Biochar can be found in all types of soils in the world as a product ofhistoric soil management practices and vegetation fires. Detailed study of dark earths enriched with biochar in the Amazon (terra chatrpreta)leads to a wider awareness of unique properties of biochar as a good soil enhancer. Biochar is a simple tool to enhance food security and diversity of cropland in areas with poorly depleted soils, less organic resources and inadequate supplies of water and chemical fertilizer. Biochar ensures water quality and quantity by enhancing soil retention of nutrients for plant utilization. There are more nutrients present in the soil instead of leaching down groundwater and causing soil pollution.

Biochar production for Climate Change:

Biochar and bioenergy co-production helps combat global climate change. This can be done by substituting use of fossil fuel by sequestration of carbon in stable carbon pools of soil. It can also reduce emissions of N2O. The carbon which is present in biochar can hold carbon in soils and resist degradation for 100-1000 years. It is made by pyrolysis or gassification, a procession which biomass is heated up in the absence of O2. Sustainable biochar practices can manufacture oil and gas byproducts which can be utilized as fueland renewable energy, in addition to producing a soil enhancer. When the biochar is buried into the ground the system becomes "carbon negative."

Agricultural Benefits of Biochar:

Agricultural Benefits of Biochar: Heat produced during biochar manufactureis used to substitute carbon positive energy from the fossils fuel. Itminimizes the requirement of chemical fertilizers, those results in low emissions of greenhouse gases from manufacture of fertilizer. Biocharimproves microbial life of soil, which results into more soil carbon storage.Biocharenhances soil fertilityby stimulation of plant growth, which leads to consumption of more carbon dioxide in a positive feedback mechanism.It alsoreduces emissions of nitrous oxide and methane. These are two potent greenhouse gases.

Biochar Removes Carbon from Atmosphere: 

According to Woolf et al, 2010, sustainable biochar implementation could make a decrease of 12 percent of anthropogenic Greenhouse Gases (GHG) emissions in a year. The study hypothesized that no conversion from food to biomass, no use of industrial treated waste biomass and extraction rates of biomass that would not result in soil erosion.The figure (Woolf et al, 2010) clears avoided emissions attributable to sustainable biochar generation or pyrolysis of biomass over hundred years, in comparison to the current biomass use. There were 3 scenariosmodeled showing different degrees of requirements on global biomass resources; red is for Maximum Sustainable Technical Potential (MSTP), blue for Medium and black for Low). Sustainable biochar is depicted by solid lines; dashed linesfor biomass combustion. In all three levels sustainable biochar trumped combustion of biomass in terms of avoided emissions of gases.

By : Shoaib Aslam