Light interception and radiation use efficiency response to narrow-wide row planting patterns in maize

The light deficiency in the canopy is not the main factor limiting maize (Zea mays L.) production but the lower radiation use efficiency (RUE). Conservation tillage planting patterns were used to construct a sustainable agricultural system for soil protection and higher RUE. On these bases, we tried to create more uniform light distribution in crop canopy for increasing radiation use efficiency by narrow-wide row planting patterns. Maize were cultivated in three planting patterns: (1) narrow-wide rows of “30 cm + 170 cm” (P1, i.e. narrow row is 30 cm, wide row is 170 cm with density 6.4 plants m), (2) “40 cm + 90 cm” (P2, i.e. narrow row is 40 cm, wide row is 90 cm with density 6.4 plants m); and (3) uniform row of “65 cm” (CK, i.e. uniform row is 65 cm with density 6.4 plants m). The mechanisms of the maize canopy creation during the growth development period were examined. Moreover, the fractions of light interception (F), leaf area index (LAI), leaf mass per unit area (LMA), canopy extinction coefficient (K) and RUE were compared. In three planting patterns, K values exhibit a P1<P2<CK feature. The differences in LMA of the three patterns were not significant (LSD, p<0.05). The fractions of light interception value (F) in P1 was significantly lower than that in P2 and CK, whereas its LAI was almost equal to that of CK and P2. RUE was the largest in P2. Therefore, with similar plant density, LAI was not affected by planting patterns. Although light interception was lower in narrow-wide row planting patterns while CK was highest in three patterns, the canopy light environment in narrow-wide row planting patterns was improved and RUE was significantly increased, especially in P2.