Influence of Foliar Nano DAP Application with Moisture Conservation Strategies on Soil Moisture, Temperature, Canopy Temperature, and NDVI in Rabi Maize (Zea mays L.) under Eastern Rainfed Condition

Currently, water hyacinth is a problematic weed, adversely affecting pond ecosystems and the environment. In eastern India, including Assam, water hyacinth (Eichhornia crassipes) is problematic, rendering water bodies like ponds and lakes unproductive due to its dominance. It can be effectively utilized as mulch in crop production. The field experiment was conducted at Assam Agriculture University, Jorhat, Assam during the period of 2022-23 and 2023-24 with the objective of evaluating the effect of different mulches and nutrient management practices on soil temperature, moisture conservation, SPAD, and NDVI values and canopy temperature of maize. The experiment was conducted in factorial RBD with 3 replications. There were three moisture conservation treatments viz., M 1 :No-Mulching, M 2 :Mulching with paddy straw @ 5.0 t/ha, M 3 :Mulching with water hyacinth @ 5.0 t/ha and seven nutrient management practices viz., N 1 :Recommended dose of fertilizer (60-40- 40 kg/ha N-P 2 O 5 -K 2 O), N 2 :75% NP & 100% K with foliar spray of nano-DAP @2ml/l at knee high and tasselling stage, N 3 :75% NP & 100% K with foliar spray of nano-DAP @4ml/l at knee high and tasseling stage, N 4 :75% NP & 100% K with foliar spray of nano-DAP @6ml/l at knee high and tasseling stage, N 5 :50 % NP & 100% K with foliar spray of Nano-DAP @2ml/l at knee hight and tasseling stage, N 6 :50 % NP & 100% K with foliar spray of nano-DAP @4ml/l at knee high and tasseling stage and N 7 :50 % NP & 100% K with foliar spray of nano-DAP @6ml /l at knee high and tasseling stage. The moisture content was recorded up to 30 cm depth (0-15 cm depth and 15-30 cm depth). The result revealed that all the treatments with mulching had higher soil temperature, higher soil moisture, and lower canopy temperature compared to no mulching treatment, but there was no significant effect of nutrient management practices on these parameters. Water hyacinth mulch treatment recorded the highest soil moisture at 10 cm depth and lower canopy temperature. The average soil moisture recorded was 17.95% under no mulch treatment and 20.27% by weight under water hyacinth mulching. Similarly, the average canopy temperature recorded was 24.18 o C under no mulch treatment and under water hyacinth mulching it was 23.76 o C and the soil temperature recorded was 19.30 o C under no mulch treatment and it was 20.02 o C under water hyacinth mulching. Normalized Difference Vegetation Index (NDVI) and SPAD values were significantly influenced by mulching compared to no mulching treatment, but there was no significant effect due to nutrient management practices. Water hyacinth mulch treatment recorded the highest NDVI, lower canopy temperature, and higher SPAD Values. The average NDVI recorded was 0.609 under no mulch treatment and 0.671 under water hyacinth mulching, the average canopy temperature recorded was 24.18 o C under no mulch treatment and 23.76 o C under water hyacinth mulching and SPAD values were 34.58 under no mulching and 37.13 under water hyacinth mulching