Pig slurry doses affect plant growth and corn grain yield

The aim was to evaluate the performance of corn grown with different doses of pig slurry (PS), compared to mineral fertilization (NPK) and without fertilization. Four doses of PS were evaluated from the need of the crop (50%, 100%, 150% and 200%), NPK and without fertilization (control), five replications each treatment, with a randomized block design under field conditions. The production of total dry matter (DM), stems (DMS) and leaves (DML), yield components ear length (EL), number of rows of grains per ear (NRGE), number of grains per ear (NGE) and number of ears per square meter (NESM), grain yield (GY) and corn harvest index. The doses of 100%, 150% and 200% of PS were equivalent to NPK, both for DM production (mean 6,077 kg/ha), and for DMS (4,000 kg/ha) and DML (2,076 kg/ha). Corn fertilized with 50% PS showed higher NESM (23) compared to the control (19) and there was no significant difference between the doses of PS and NPK (mean 20.9). The 200% PS dose matched the NPK treatment in NGE (mean 412), NRGE (12.1) and GY (12,674 kg/ha). The PS doses of 50, 100 and 150% of the recommended are not equivalent to NPK fertilization, reducing, respectively, 175, 115 and 114% of GY.