Effects of Farmyard Manure and BiocharTreatments on the Development and Water Use of Lettuce Under the Deficit Irrigation Regime

Ergüler D., Okyay F., Şenol Ö., Yerli C.

TURKISH JOURNAL OF AGRICULTURE: FOOD SCIENCE AND TECHNOLOGY, vol.12, no.2, pp.274-283, 2024 (Peer-Reviewed Journal)


In this study, the effects of different organic matter additives[soil (control), 20 ton ha-1farmyard manure,  20 ton ha-1biochar,  and  10  ton  ha-1farmyard  manure+10  ton ha-1biochar] to the  soil of lettuce  grown  with  different  irrigation  water  levels [100%  (full  irrigation),  75%  (25%  deficit irrigation), 50% (50% deficit irrigation), and 25% (75% deficit irrigation)]on water and irrigation water  productivity  efficiencies  and  plant  characteristics  were  investigated.  Among  the  organic matter additives, the biochar reduced the amount of irrigation water and actual evapotranspiration of lettuce and increased its marketable yield, thus the highest water and irrigation water productivity efficiencies were obtained from biochar treatment. Despite the decreasing marketable yield in the 50%  irrigation  treatment,  the  proportionally  decreasing  amount  of  irrigation  water  and  actual evapotranspiration caused the highest water and irrigation water productivity efficiencies to occur in the 50% irrigation treatment. While the root diameter, root fresh and dry weights, stem diameter and  length,  head  fresh  and  dry weights,  marketable  leaf  number  and  yield,  chlorophyll,  and  leaf relative water content of lettuce decreased with decreasing irrigation water levels, root length and membrane  damage  increased.  The  effects  of  organic  matter additiveson  all  of  these  physical-physiological properties, except root diameter and membrane damage, were found to be significant, and  the  biochar  provided  the  most  effective  development  of  these  parameters  under  the  deficit irrigation regime. Considering that the yield and yield characteristics in 75% irrigation treatment do not decrease at a very significant level compared to full irrigation (100%) and that these decreases can  be  compensated  by  biochar  and  that  the  farmyard  manure+biochar  as  alternative  treatment  is also  effective  in  improving  the  decrease  in  yield  parameters,  treatment  of  10  ton  ha-1farmyard manure+10 ton ha-1to the soil at 75% irrigation water level was found to be recommended in lettuce cultivation.