Smallholder farmers dominate agriculture in Nepal. These farmers have poor knowledge about agriculture and lack of support for soil management and integrated plant-nutrient systems. Focusing on the importance and need for soil-fertility management, a soil-testing mobile van program has recently been introduced in Nepal by Soil Management Directorate, Hariharbhawan. With the introduction of the mobile lab, famers can get their soil tested for nutrient deficiencies and fertilizer requirements at their doorsteps. Using mobile lab, spatial distributions of chemical properties, including pH, organic matter (OM), total nitrogen (N), available phosphorus (as P 2 O 5), and available potassium (as K 2 O) were examined in soil samples taken from the 0 to 15 cm depth from selected agricultural fields in eight different districts in the mid-hills and Terai regions of Nepal. Tests conducted on 1,479 soil samples in the soil-testing mobile van revealed the following: the mean soil OM ranged from 0.01 to 1.77%; total N content ranged from 0.01 to 0.08%; mean available P 2 O 5 ranged from 16.47 to 197.82 kg ha −1 ; and mean available K 2 O digitalcommons.unl.edu RPa n d e y e t a l. i n J o u r n a l o f C r o p I m p r ov e m e n t 3 2 (2 0 1 8) 2 ranged from 84.3 to 422.57 kg ha −1. For each crop to be grown, farmers were provided with individual soil health reports and fertilizer recommendations (rate, amount, and type). This program not only allows scientists and farmers to work closely and share information but also serves as a model for the nation to successfully transfer technology for improving soil health and sustainability.

This study was conducted to determine the amount of naturally occurring radioactivity in the soil of Nepal's Kathmandu valley. The activity of naturally occurring radionuclides was determined in these soil samples using a sodium iodide detector. Activity concentrations of 238U, 232Th, and 40K were found in the range: 32.00-111.38 Bq kg-1, 33.52-130.04 Bq kg-1, and 342.50-897.71 Bq kg-1, respectively. These values are well within the permissible range as recommended by UNSCEAR. The soil samples with the highest activity concentrations were primarily found in the valley's northern region. The activity concentrations were also used to calculate the radiation hazard indices: the mean value obtained were 96.63 nGy hr-1 for Absorbed Gamma Dose Rate in Air, 200.04 Bq kg-1 for Radium Equivalent Activity, the 0.12 mSv yr-1 for Annual Effective Dose, and 0.55 for External Hazard Index. These calculated hazard indices were used to estimate the potential radiological health risk from the soil, and the dose rates associated with it were significantly less than their permissible limit. The overall findings indicate no radiological threat to the population's health in the study area. Additionally, the findings of this study provide baseline information on potential radionuclides that contribute mostly for radiation exposure from natural sources.

A field experiment was conducted at IAAS agronomy farm, Rampur, Chitwan, Nepal from Nov. 2012 to Aug. 2013 to improve soil fertility and production of maize through the inclusion of leguminous winter cover crops in the cropping system. The experiment was conducted for two seasons in single factor randomized complete block design (RCBD) with eight treatments and three replications. Five N fixing legume crops: chickpea (Cicer arietinum), garden pea (Pisum sativum var. sativum), field pea (Pisum sativum var. arvense), lentil (Lens culinaris) and grass pea (Lathyrus sativus); one N fixing legume fodder: Berseem (Trifolium alexandrinum); one non-fixing legume: rajma bean (Phaseolus vulgaris); and maize (as a control) were cultivated in the first season and on the following season maize was cultivated in all plots after incorporating former crop residues. Rajma bean covered the highest area at an early stage but field pea and grass pea covered the maximum land area at a later stage. The highest dry matter production (2.32 t/ha) and nitrogen content in residues (2.57%) were obtained from lentil. Cultivation of leguminous winter cover crops had no significant effect on soil parameters. However, the incorporation of legume residues had significant effects on organic matter content, total nitrogen and available phosphorus in soils. The highest soil organic matter (3.03%) and total nitrogen (0.15%) was observed from field pea plots while the highest available phosphorus (36.00 kg/ha) was from berseem plots. Legumes cultivation and their residues incorporation into the soil had significant effects on grain, straw and dry matter yields of succeeding maize crop. Grain (3.92 t/ha), straw (5.39 t/ha) and dry matter (9.31 t/ha) yields were the highest from lentil plots while the lowest grain (2.51 t/ha), straw (3.96 t/ha) and dry matter (6.48 t/ha) from control plots. Total nitrogen uptake by maize was significant and it was the highest (141.90 kg/ha) from lentil plots and the lowest (109.80 kg/ha) from control plots. Cultivation of lentil in the winter produced satisfactory land coverage and incorporation of its residues into the soil was the best for improving soil fertility and succeeding maize yield under the Chitwan condition of Nepal.