TY - JOUR
T1 - Crop Performance Indexes Applied to Legume Used as Summer Cover Crops under Water Deficit Conditions
AU - Berriel, Verónica
AU - Perdomo, Carlos H.
AU - Signorelli, Santiago
AU - Monza, Jorge
PY - 2022/2
Y1 - 2022/2
N2 - Summer legume cover crops (CC) such as Crotalaria juncea, Crotalaria spectabilis, Crotalaria ochroleuca, and Cajanus cajan could offer diverse advantages for the environment and productive cropping systems. A low transpiration efficiency (TE) of CC can induce soil water content to levels that present a challenge for the subsequent crop. In a 75-day growth chamber experiment, using the natural abundance of13C,18O, and15N we evaluated the TE and BNF under two soil water conditions. Our results showed that the four species tested are good candidates for their use as CC because they showed good results in terms of productivity parameters, TE, and BFN. Cajanus cajan had the highest TE, a high shoot dry matter production, and accumulated more N from BFN in the shoot than C. spectabilis, C. juncea, and C. ochroleuca. Δ18O increased under moderate water deficit and showed an inversely proportional relationship with the amount of transpired water, supporting the use of this isotopic indicator as a proxy for transpiration and stomatal conductance. For the isotopic parameters no interaction between the factors water regimen and species were found. We propose the mass ratio of nitrogen fixed by the volume of transpired water and the isotopic discrimination of13C as useful indicators of drought fixing legumes tolerance.
AB - Summer legume cover crops (CC) such as Crotalaria juncea, Crotalaria spectabilis, Crotalaria ochroleuca, and Cajanus cajan could offer diverse advantages for the environment and productive cropping systems. A low transpiration efficiency (TE) of CC can induce soil water content to levels that present a challenge for the subsequent crop. In a 75-day growth chamber experiment, using the natural abundance of13C,18O, and15N we evaluated the TE and BNF under two soil water conditions. Our results showed that the four species tested are good candidates for their use as CC because they showed good results in terms of productivity parameters, TE, and BFN. Cajanus cajan had the highest TE, a high shoot dry matter production, and accumulated more N from BFN in the shoot than C. spectabilis, C. juncea, and C. ochroleuca. Δ18O increased under moderate water deficit and showed an inversely proportional relationship with the amount of transpired water, supporting the use of this isotopic indicator as a proxy for transpiration and stomatal conductance. For the isotopic parameters no interaction between the factors water regimen and species were found. We propose the mass ratio of nitrogen fixed by the volume of transpired water and the isotopic discrimination of13C as useful indicators of drought fixing legumes tolerance.
KW - Biological nitrogen fixation
KW - Cover crops
KW - Drought
KW - Legumes
KW - Nitrogen use efficiency
KW - Stable isotopes
KW - Water use efficiency
UR - http://www.scopus.com/inward/record.url?scp=85125556477&partnerID=8YFLogxK
U2 - 10.3390/agronomy12020443
DO - 10.3390/agronomy12020443
M3 - Article
AN - SCOPUS:85125556477
SN - 2073-4395
VL - 12
JO - Agronomy
JF - Agronomy
IS - 2
M1 - 443
ER -