Soil Chemical Properties Under Conservation Agriculture and Cereal-Based Cropping System in Eastern Tarai of Nepal

Field experiments were conducted for four years (2014-2017) at five locations namely Salbani, Bhokraha, Simariya, Bhaluwa and Kaptanganj of Sunsari district to assess the changes in soil chemical properties under conservation agriculture (CA)-based practices in two cropping systems namely rice-kidney bean-maize at Salbani and rice-wheat at rest of the locations. In rice-wheat cropping system, there were four treatments: (1) conventional tillage (CT) for rice transplantation and subsequent wheat sowing, (2) conventional tillage rice transplantation followed by zero tillage (ZT) wheat, (3) unpuddled rice transplantation followed by zero tillage wheat, (4) zero tillage in both rice and wheat. Similarly, in rice-kidney bean-maize cropping system, there were four treatments; (1) conventional tillage for rice transplantation and sowing of both kidney bean and maize, (2) conventional tillage rice transplantation followed by zero tillage in both kidney bean and maize, (3) unpuddled rice transplantation followed by zero tillage in both kidney bean and maize, (4) zero tillage in all three crops. Soil samples were taken at initial and every year after rice harvest.The soil samples were analyzed for total nitrogen, available phosphorus, available potassium, pH and soil organic matter.Total nitrogen (N) showed a slightly decreasing trend in the first three years and showed a slight increase at the end of experiment under ZT in all locations. The total N under ZT changed from 0.12 to 0.13%, 0.05 to 0.06%, 0.10 to 0.12%, 0.11 to 0.08% and 0.09 to 0.13% in Salbani, Bhokraha, Simariya, Bhaluwa and Kaptanganj, respectively.  All locations showed the positive values of available potassium; Salbani  revealing considerable change of 64.3 to 78.5 mg/kg in CT while 68.4 to 73.3 mg/kg in ZT condition. The treatment where rice was transplanted in unpuddled condition and zero tilled to wheat, had a mean value of available phosphorus and potassium as 87.3 and 81.9 mg/kg respectively. Soil pH ranged from 4.8 to 7.1 in CT while it was 5.2 to 6.8 in ZT across the locations. The change in soil organic matter in CT of all locations except Salbani was narrower as compared to ZT

Conservation Agriculture Mitigates the Effects of Climate Change

Intensive tillage based conventional agriculture have high global warming potential. Alternative to this, conservation agriculture (CA) systems utilize soils for the production of crops by reducing excessive tillage, maintaining crop residue on the soil surface, and adoption of crop rotations. The paper attempts to review the findings of CA based experiments under different cropping systems within and outside of the country. It has been found that CA increases and sustains the crop productivities, mitigates green house gas emissions from agriculture by enhancing soil carbon sequestration, improving soil nutrient status and water use efficiencies, and reducing fuel consumption. Mainstreaming of CA systems in Nepal is hindered by its knowledge gap, inadequate farm machineries and tools, small holdings, poor infrastructures, and lack of CA friendly policy support. Therefore, there is an urgent need to test, verify and scale-out the CA based technologies by Nepal Agricultural Research Council (NARC) across the different agro-ecologies through farmer-centered partnership among the International institutions, public and private sector of Nepal. &nbsp

Managing Weeds In Dry Direct Seeded Rice: A Profound Challenge

Dry Direct Seeded Rice (DDSR) is a promising technology to address environmental, water, labor and profitability issue that is constantly threatening the rice farming community around the world. Rice yield under DDSR is primarily limited due to weeds. There are instances of complete crop failure in DDSR owing to poorly managed weeds. More than 50 weeds species infest DDSR crop due to aerobic nature of soil confronting a major challenge in the wide spread adoption of dry direct seeding. Direct-seeded rice faces a potential threat from changes in the competing weed flora, with an increase in those species that are difficult to control. This review article presents the prospects of DDSR along with the available weed management strategies such as preventive, physical, chemical, cultural and biological methods and their judicious use. Over reliance on only one approach of managing weeds may be back firing as well. The use of chemical means are getting popular in an alarming rate for being cost effective, without calculating the environmental concerns which might lead to herbicidal resistance and negative consequences to environment and human health. Therefore, it is necessary to understand the environment while shifting from transplanted rice to dry direct seeding, identifying weeds flora and choosing or integrating the best weed management practices foreseeing the future consequences. The logical integration of available weed management options that is ecologically sound, economic and effective for season long weed control is the main essence that ensures the sustainability of rice production.</jats:p