Effect of Cow and Poultry Manure Particle Size on Growth and Yield Performance of Barley (Hordeum vulgare L.) under Sandy Loam Soil Conditions

Abstract

The optimization of organic manure application is of great importance for sustainable crop production, but how the agronomic performance will vary according to manure source and particle size is not well explored. The four different particle-size fractions of cow (C1–C4) and poultry (H1–H4) manure, as well as an unfertilized control, were tested for their effects on the growth and yield of the crop barley in a randomized complete block design in sandy loam soil. Organic amendments had a significant (p < 0.001) influence on all the measured traits and accounted for 96–99% of the total variance. The particle size was the dominant factor for biological yield, and the manure type × particle size interaction was the primary determinant of grain quality traits, with particle size also having a significant effect. The use of finer cow manure (C4) and intermediate poultry manure (H3, H4) resulted in the highest biological yield of 1450 g m−2, the highest spike density, and tillering. In contrast, the coarser fractions (C1, C2, H1, H2) were found to be more supportive of vegetative elongation and grain filling. Multivariate analysis clearly segregated treatments according to biomass versus grain-quality trajectory, and spike density was determined as the most important factor affecting biological yield, as was tillering. In conclusion, making manure particle size adjustments to specific agronomic targets offers a reliable and precise approach to maximizing barley productivity and soil nutrient use.