Use of multinutrient diagnosis under different tillage systems on corn productivity under calcareous soil conditions [electronic resource].

Includes references.

Diagnosis and Recommendation Integrated System (DRIS) applies nutrient ratios instead of the isolated concentration values of each nutrient in interpretation of tissue analysis. The objectives of this research were to establish adequate DRIS norms for com grown on two rates of N, P and K under two tillage systems and correlate indices of nutrition balance with yield. The study was established on calcareous soil, Maryut soil. Two rates ofN, P, and K (75 and 150 kg N/fed., 22.5 and 45 kg P20Jfed., and 24 and 48 kg K20/fed.,respectively),were applied to plots managed with two tillage systems: chisel plow and moldboard plow. Obtained data show that corn grain yield increased with increasing N, P and K rates. The com grain yield was affected by interaction between tillage and N¬and P-rate. Maximum yield within moldboard plow system was achieved with the rate N2P2K2 (39.16 kg grain/plot). DRIS norms for several elements (N, P, K, Fe, Mn, and Zn) calculated from the data bases were significantly different, while norms for the other nutrients (Ca, Mg, and Cu) were not. Results of this test indicate that the DRIS norms show imbalanced nutrition compared to high-yield under the two studied tillage systems. Nitrogen indices were always sub-optimal in all treatments under the two tillage systems (except, P2K2N2 treatment). K indices were commonly sub-optimal (except, P2K2Nl and P:zK2N2 treatments under chisel tillage). Also, P indices were commonly sub-optimal (except, P2KIN2, P2K2Nl and P2K2N2 treatments under the two tillage systems, usually close to supra¬optimal). The diagnosis continued in this progressive manner,

Summary in Arabic.

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