Response of crisp lettuce (Lactuca sativa L.) to organic and inorganic sources of fertilization

Abstract

The use of organic products to promote plant growth is becoming ever-more important as the paradigm of sustainable production of foodstuffs becomes increasingly common. Accordingly, the objective of the current study was to evaluate the response of lettuce to organic and inorganic sources of nutrients in soils representative of those found in Parana State, Brazil, across successive cultivations. Experimental methodology involved randomized blocks, with5 repetitions. Treatments used were: 1- control (Test);2-100% mineral fertilizer (MF); 3- 100% chicken litter (CL); 4- 100% liquid pig manure (LMP); 5- 50:50 mixture of CL and MF (CL+MF); 6- 50:50 mixture of LMP and MF (LMP+MF) and 7- 50% CA + 50% (CL+LMP). Experimental plot size was 0.7 m², and young Verônica cultivar individuals were planted with a 0.30 x 0.30 m spacing. There were two experimental plantings: in the first, the first using the treatments described above; the second, investigated the residual effect of fertilization of the first planting. For the first cropping, highest wet (326.5 and 315.4 g plant-1)and dry (14.2 and 19.74 g plant-1) above ground biomasses, were obtained with the LMP +MF and CL+MF treatments. No significant differences were encountered for the treatments in the second harvest. The effect of mineral fertilization in the production of Veronica cultivar lettuce, is greatest when it is combined with organic fertilization such as chicken litter (CL) or liquid pig manure (LMP).