Improving fertilizer recommendations for Nepalese farmers with the help of soil-testing mobile van

Abstract

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.

Digital soil mapping in the Bara district of Nepal using kriging tool in ArcGIS

“…Despite the successful application of DSM in regions around the world, no single study has examined the use of DSM to represent soil nutrient variability in any part of Nepal. The commonly practiced soil fertility assessment is based on a random soil sampling protocol to obtain an average fertility value for a farmer’s field [ 22 ]. It ignores spatial variability, or those soil testing results that do not provide randomness of variations from one place to another.…”

Spatial Variability of Soil Properties under Different Land Use in the Dang District of Nepal

“…However, the P in agricultural land (11.89 kg ha −1 ) was not significantly different from agroforestry or grassland at P < 0.05. Higher P content in the agricultural lands could be explained by the application of P-containing fertilizer (such as DAP, which contains 18% N and 46% P) (Pandey et al, 2018), and by the application of manure including FYM for soil fertility (Miheretu & Yimer, 2018). The study area was dominated by low and medium classes of soil P ( Figure 6).…”

“…As a result, there is no crop residue in the field as a source of organic amendments. Application of farmyard manure (FYM), urea, di-ammonium phosphate (DAP), and muriate of potash (MOP) are the most common nutrient sources in the study area (Pandey et al, 2018). The source of trace elements in the agriculture land is only through FYM through which micro-nutrient addition is insignificant.…”

“…The literature reveals that Nepal is dominated by moderately acidic soils due to parent material (such as sandstone, siltstone, quartzite, and shale), loss of major cations during monsoon season, and the atmospheric nature of aluminum in these soils (Ghimire & Bista, 2016;Pandey et al, 2018). However, soils in the western part of Nepal are dominated by alkaline parent material, along with the presence of base-forming cations associated with carbonates and bicarbonates found naturally in soils and irrigation water.…”

“…A relatively lower amount of soil OM in the agricultural soils may be associated with the removal of crop residues (Awasthi, Singh, & Sitaula, 2005). A recent study by Pandey et al (2018) reported that the intensive tillage for crops in parts of Nepal lowered nutrient concentration and soil OM, thereby declining soil fertility.…”