Dados do Trabalho

Título

GLOMALIN FRACTIONS IN ONION NO-TILL SYSTEM

Resumo

Glomalin is a glycoprotein produced by arbuscular mycorrhizal fungi (AMF) that contributes to soil aggregation. The use of plants that do not associate with AMF may reduce their concentration in the soil. We evaluated the effect of the mycotrophic character of winter cover crops on glomalin fractions during crop rotation in a no-tillage vegetable system (NTVS) of onion. The work was carried out in an experimental area in onion NTVS to 13 years. The treatments were black-oats (BO) (mycotrophic) single, oilseed-radish (OR) (non-mycotrophic) single, BO+OR intercropped and fallow (weeds) in winter, followed by onion (Allium cepa) in spring and velvet-bean (Mucuna aterrima) in summer, in a randomized block design. The easily (EG) and total (TG) glomalin fractions were extracted from soil samples collected at the end of the onion, velvet-bean and cover crop cycles between 2020/21, using sodium citrate (20-50 mM), high temperature (121oC) and pressure (1.1 kg cm-2). After the onion, EG was 2.5; 2.7 and 2.6 mg g-1 soil for BO, BO+OR and fallow, respectively, higher than OR, which produced 1.9 mg g-1 soil. TG values were 7.1 and 7.6 mg g-1 soil for BO and BO+OR, higher than NF and fallow, which produced 6.3 and 5.7 mg g-1 soil, respectively. After velvet-bean, the EG of the BO+OR intercropped was 2.1 mg g-1 soil, higher than BO (1.5 mg g-1) and OR (1.4 mg g-1). In the same period, the EG was 1.2 mg g-1 in the fallow, lower than BO, but without differing from OR. TG after mucuna showed no difference between treatments. After the winter cover crops, EG was 1.7 mg g-1 for BO and BO+OR, respectively, higher than OR and fallow which produced 1.2 and 1.0 mg g-1. In the same period, TG was 9.0 mg g-1 soil for BO, higher than BO+OR and fallow (8.2 and 8.0 mg g-1, respectively), which was higher than NF (7.0 mg g-1 soil). Oilseed-radish reduces EG and TG content in no-tillage vegetable systems.

Palavras-chave

AMF; Allium cepa; Cover crops; Mycotrophic; NTVS.

Instituição financiadora

Agrisus, Capes, CNPq.

Agradecimentos

Agrisus, CNPq, EPAGRI, PPGRGV.