In Nepal, Rice-Maize-Wheat is a dominant cropping system where rice is the principal food grain crop. Among three geographical classification; high himalayas, hills and Terai, most lands in Terai are suitable for rice cultivation (73% of total rice production accounted by Terai), only a small fraction of land in the hills and mountains are suitable for rice cultivation  [ Tripathi et.al. 2018]. Rice is generally cultivated by transplanting young seedlings into flooded field condition where water stagnation is maintained by mud bunds around the field. Despite being the second richest country in water resources in the world, chronic shortages of water at various places of the country is a common problem [Deshar, Bashu Dev. (2013)]. Agricultural irrigated land in Nepal was reported at 29.74 % in 2010, according to the World Bank collection of development indicators, compiled from officially recognized sources. As major portion of total cultivable land is rainfed, farmers have to depend on seasonal rainfall also for rice cultivation. Agriculture is the single largest user of freshwater resources, using a global average of 70% of all surface water supplies according to Ongley, (1996). Irrigated rice accounts for 56% of the total rice area in Nepal.
Thus, large rice production still occurs under rainfed condition. Out
of the 44% of rainfed rice area, 39% is rainfed lowlands and 5% is
rainfed upland. Even for the irrigated rice area, the supply of water is not highly reliable with the production conditions in large area resembling that of the rainfed environment [Tripathi et.al.(2018)].
In the areas of semi-commercialized agriculture, farmers are injudiciously using various pesticides for an increased productivity and risk mitigation in crop production, even though an average application rate of 142 g/ha (Adhikari, 2002) and annual consumption of 176mt a.i. (Palikhe, 2002) of pesticides in Nepal is not considered high. According to Palikhe (2006), more than 60% of the applied pesticide remains in the soil materials polluting soil environment as a risk to terrestrial as well as aquatic biosphere.
The issue of accelerated erosion was developed from a number of studies and
impressionistic writings, which claimed that Nepal would slide away into Ganges by the year 2000 and that the Nepalese hill farmer was to blame for this situation (Biot, 1995:96). This all soil would pass through the way of Terai plains. The frequent breaking and loosening of soil through regular hoeing and plough had forced soil to erosion. Soil degradation through nutrient depletion is also a serious issue (Lal, 2000)
Many studies have shown that soils in mid-hills have very low nutrients especially nitrogen and phosphorous (Shah and Schreier, 1991). In particular, the double and triple annual cropping rotations are more nutrient demanding. Thus in order to fulfill nutrient requirements, increased number of crops per annum has increased the inputs of chemical fertilizers in their farm. As a
consequence of increased fertilizer use during intensification process, soils in mid-hills are becoming more acidic (Westarp, 2004) During the monsoon time, heavy rainfall takes away tons of soil with nutrients from hills to the water bodies. It has been found that water bodies near to the intensification area have higher concentration of nitrogen, phosphorous and potassium. This is due to higher amount of chemical fertilizer use for intensive production of crops and the nutrients have been washed down (Dahal, 2007).
In my locality, which is inner Terai region, fields where rice is cultivated every year, most of them are rainfed with poor drainage facility, other than nearby water bodies, which carries all the effluents all way long from the hills. Due to this greater flow of water in water bodies aided by loose and moist soil, caused by regular tillage, lack of drainage constructions and no proper embankment of water bodies nearby, they burst out into farmers' field and wipe away top fertile soil with them degrading cultivable land as well as contaminating various water bodies on their way. During monsoon period, even when such flooding do not occur, presence of rodents, crabs and many other field insects create cave like seepage ways through which significant amount of water from rice field flows into nearby water bodies, taking some amount of top fertile soil too.
This overall situation of land degradation has influenced farmer's economy, both farm and environmental sustainability and socially, people are still unaware about the losses they are subjected to from such conditions.
Proper land levelling of fields with well managed drainage as well as irrigation system and good agricultural practices are very essential for the management of this situation as far I think. This problem has to be addressed as soon as possible keeping the triple bottom line in mind by every responsible person out there in Agriculture field.

References:
i. Bhaba P Tripathi., et al. “Rice Strategy for Nepal". Acta Scientific Agriculture 2.9 (2018): 171-180.
ii. Biot, Y.,(1995). Rethinking research on land degradation in developing countries. World Bank Discussion Papers, pp. 96
iii. Dahal, B. D., (2007). Effects of agricultural intensification on the quality of rivers in rural watersheds of Nepal. Journal of Food, Agriculture and Environment, 5(1): 341-347
iv. Deshar, Bashu Dev. (2013). An Overview of Agricultural Degradation in Nepal and its Impact on Economy and Environment. Global Journal of Economic and Social Development. 1. 1-20.
https://www.researchgate.net/publication/320146140_An_Overview_of_Agricultural_Degradation_in_Nepal_and_its_Impact_on_Economy_and_Environment
v. Lal, R., (2000). Controlling greenhouse gases and feeding the globe through soil management. The Ohio State University, Columbus, Ohio
vi. Ongley E. D., (1996). Control of water pollution from agriculture. Food and Agriculture Organization of the United Nations, Burlington, Canada.
vii. Palikhe, B.R., (2002). Pesticides and the Environment. Agriculture and Environment Journal, MoAC, Kathmandu, Nepal.
viii. Palikhe, B.R., (2006). Pesticides as Water Pollutants. Agriculture and Environment Journal, MoAC, Kathamndu, Nepal.
ix. Shah, P. B. and H. Schreier, (1991). Soil fertility and erosion issues in the middle mountains of Nepal. Workshop Proceedings. Kathmandu, Nepal.
x. Westarp, S.V., (2004). Agricultural intensification and the impacts on soil
fertility in the Middle Mountains of Nepal. Canadian journal of Soil Science 323-332.