Application of SRF by a farmer on her rice field (H.PG.T.N. Kualasinghe)
Rice husks are often considered as a waste, and its carbon is released to the atmosphere as carbon dioxide (CO2) which is a greenhouse gas (GHG) through either decomposition or burning as a biofuel. However, rice husks can be converted into biochar – where its carbon is stable - with a large number of micro and sub-micron size pores in a honeycomb-like structure. Rice husk biochar was produced using an improved batch pyrolizer, “Kunthaniya”, at a temperature of between 450°C and 650°C. Pore spaces in rice husk biochar can be intercalated (filled) with urea and then, slow-release fertilizer (SRF) pellets can be produced through the use of a suitable biodegradable binder. This SRF has found to be more efficient in improving the N-use efficiency, hence the urea requirement of paddy fields in Sri Lanka can be reduced by about 25%, further contributing to environment sustainability. It has been well documented that biochar can improve soil physical, chemical and biological properties in a sustainable manner. This process is a contribution to creative recycling of agricultural waste.
The SRF technology was evaluated against current farmer practice in rice cultivated area in Mahakanumulla village, Anuradhapura district, Sri Lanka. The area belongs to the Dry Zone of Sri Lanka (mean annual rainfall <1750mm). Rice is cultivated during two seasons, yala (May-September) and maha (December – February): the yala season is generally drier. Farmers rely on irrigation water supplied from a small village tank. The SRF was transported to farmers’ fields and applied at 2 weeks (@ 100 kg/ha), at 4 weeks (@ 170 kg/ha) and 7 weeks (@ 145 kg/ha) after direct seeding.
Farmers indicated that the granule size was large and light, hence they had some concerns about even distribution of fertilizer. They perceive that plants receive N slowly compared to granular urea - suggesting the slow releasing nature of the new technology. They did not observe any yield difference. Obtaining rice husks in large quantities from rice mills to produce biochar can sometimes be difficult in some areas of the country due to competition for use in the poultry industry. Some farmers may be discouraged to implement this technology due to lack of knowledge: this can be overcome through extension officers operating at field level.
This new technology qualifies as a sustainable land management practice in number of ways. First it increases N-use efficiency in paddy fields, second it reduces the urea requirement by 25% while sustaining productivity, third it recycles agricultural wastes in paddy fields, fourth, repeated application of SRF improves soil fertility through rice husk biochar, and finally it reduces GHG emissions.
الموقع: Mahakanumulla village, Thirappane, North Central Province, سريلانكا
عدد مواقع تنفيذ التقنيةالتي تم تحليلها: 2- 10 مواقع
انتشار التقنية: يتم تطبيقها في نقاط محددة/ تتركز على مساحة صغيرة
في منطقة محمية بشكل دائم؟: كلا
تاريخ التنفيذ: 2021
نوع التقديم
| تحديد المدخلات | الوحدة | الكمية | التكاليف لكل وحدة (LKR) | إجمالي التكاليف لكل مدخل (LKR) | % من التكاليف التي يتحملها مستخدمو الأراضي |
| العمالة | |||||
| Manufacturing SRF | Labour days | 2,5 | 1500,0 | 3750,0 | |
| الأسمدة والمبيدات الحيوية | |||||
| Urea | kg | 200,0 | 270,0 | 54000,0 | |
| مواد البناء | |||||
| Binding materials 1 | kg | 10,0 | 25,0 | 250,0 | |
| Binding materials 2 | kg | 10,0 | 250,0 | 2500,0 | |
| Rice husk biochar | kg | 200,0 | 50,0 | 10000,0 | |
| إجمالي تكاليف إنشاء التقنية | 70'500.0 | ||||
| إجمالي تكاليف إنشاء التقنية بالدولار الأمريكي | 256.36 | ||||
| تحديد المدخلات | الوحدة | الكمية | التكاليف لكل وحدة (LKR) | إجمالي التكاليف لكل مدخل (LKR) | % من التكاليف التي يتحملها مستخدمو الأراضي |
| العمالة | |||||
| Labour for SRF application | Labour days | 3,0 | 1500,0 | 4500,0 | 100,0 |
| إجمالي تكاليف صيانة التقنية | 4'500.0 | ||||
| إجمالي تكاليف صيانة التقنية بالدولار الأمريكي | 16.36 | ||||
The villagers of Mahaknumulla have access for most of the resources like infrastructure and energy/electricity/fuel. But most of the villagers/landusers complain about technical assistant/support for agricultural practices, finding markets for their produce and availability of good quality drinking water. The villagers go to nearby shops to buy day-to-day needs, but they have to go to the town, which is 8-10km away, for other services such as health and financial services.
الكمية قبل الإدارة المستدامة للأراضي: 6.5 t/ha (two seasons)
الكمية بعد الإدارة المستدامة للأراضي: 6.9 t/ha (two seasons)
Although farmers could not observe a yield increase , experimental evidence suggests upto10% yield increase compared to farmer fertilizer management. A decrease in yield however not observed by farmers despite 25% reduction in N input. The above figures are for average of five farmers over two seasons.
الكمية قبل الإدارة المستدامة للأراضي: LKR 60,750.00/ha for urea
الكمية بعد الإدارة المستدامة للأراضي: LKR 70,500/ha for SRF
LKR 270/kg urea and LKR 167/kg of SRF. Expenses were calculated assuming all other costs are constants under two situations
الكمية قبل الإدارة المستدامة للأراضي: LKR 520,000/ha
الكمية بعد الإدارة المستدامة للأراضي: LKR 552,000/ha
LKR 80/kg of paddy. Average yields mentioned above was used to calculate the farm income. Therefore, farm income is expected to be increased more than the expenses in SRF applied fields.
Although a longer time is required for SRF application because of higher bulk volume (175kg more), this application cost is negligible
Expected improvements in productivity due to SRF application could strengthen the food security
Farmers gain awareness through extension programmes when implementing the SRF technology
N accumulation in water bodies is reducing due to lower N losses of SRF
It is expected to have a better moisture content as a result of accumulation of biochar with repeated application of SRF
Experimental evidence suggests that soil cover is more with rice plants that grow better and tiller more due to better N utilization for crop growth
الكمية قبل الإدارة المستدامة للأراضي: N uptake: 167 kg of N/ha
الكمية بعد الإدارة المستدامة للأراضي: N uptake: 219 kg of N/ha
Higher uptake of N by rice plants due to SRF application, nutrient recycling is expected to be improved. The above values were obtained from 5 farmer fields in the year 2021.
الكمية قبل الإدارة المستدامة للأراضي: Electrical Conductivity : 0.11 dS/m
الكمية بعد الإدارة المستدامة للأراضي: Electrical Conductivity : 0.09 dS/m
The above values were obtained from 5 farmer fields in the year 2021.
SRF contains biochar which is a good source to improve the soil C.
الكمية قبل الإدارة المستدامة للأراضي: pH : 7.42
الكمية بعد الإدارة المستدامة للأراضي: pH : 7.38
The above values were obtained from 5 farmer fields in the year 2021.
Efficient uptake of N cause to improve the crop growth, thereby vegetation cover
الكمية قبل الإدارة المستدامة للأراضي: 5.2 t/ha (straw) + 8.1 (grain)
الكمية بعد الإدارة المستدامة للأراضي: 6.0 t/ha (straw) + 8.7 t/ha (grain)
Higher crop growth results higher biomass production. The above values were obtained from 5 farmer fields in the year 2021.
Because of the better growth of the rice plants micro climate in the paddy fields is expected to be improved.
N accumulation in water bodies is expected to be reduced due to lower N losses from SRF
