Limits...
Rice Yield and the Fate of Fertilizer Nitrogen as Affected by Addition of Earthworm Casts Collected from Oilseed Rape Fields: A Pot Experiment

View Article: PubMed Central - PubMed

ABSTRACT

The mechanism associated with improvement of soil nutritional status by oilseed rape crop, leading to better performance of rice crop, in rice-oilseed rape cropping systems is little known. The present study was aimed to test the hypothesis that earthworm casts produced during oilseed rape-growing season have positive effects on grain yield and fertilizer nitrogen (N) utilization in the subsequent flooded rice crop. A 15N-tracing pot experiment was conducted to determine the effects of earthworm casts collected from oilseed rape fields on yield attributes in rice and the fate of fertilizer N. Soil treated with earthworm casts (soil: earthworm casts = 4: 1, w/w) (EC1) produced 39% higher grain yield than soil only (EC0). EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. Aboveground biomass and harvest index were higher in EC1 than in EC0 by 20% and 15%, respectively. SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0 at 15 and 20 days after heading, respectively. EC1 had 19% higher total N uptake and 18% higher physiological N-use efficiency than EC0. These positive effects of earthworm casts on yield attributes offset negative effects of decreasing N rate from 0.74 g pot–1 (equivalent to the recommended field rate of 150 kg ha–1) to 0.44 g pot–1 (equivalent to 60% of the recommended rate). Fertilizer N retention rate was 7% higher while fertilizer N loss rate was 6% lower in EC1 than in EC0. Our study suggests that earthworm casts produced during oilseed rape-growing season are expected to have the following benefits on the subsequent flooded rice system: (1) improving growth and physiological processes in rice plants and consequently increasing rice grain yield, and (2) increasing fertilizer N retention rate and hence decreasing fertilizer N loss rate and reducing environmental risk.

No MeSH data available.


Effects of addition of earthworm casts on SPAD values in flag leaves in rice.EC0, soil only; EC1, soil: earthworm casts = 4: 1 (w/w). Data are the means across two N rates. Vertical bars represent SE (n = 6).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5120869&req=5

pone.0167152.g002: Effects of addition of earthworm casts on SPAD values in flag leaves in rice.EC0, soil only; EC1, soil: earthworm casts = 4: 1 (w/w). Data are the means across two N rates. Vertical bars represent SE (n = 6).

Mentions: EC1 produced 39% higher grain yield than EC0 (Table 2). EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. There were no significant differences in spikelet number per panicle and grain weight between EC1 and EC0. Aboveground biomass and harvest index were 20% and 15% higher in EC1 than in EC0, respectively. Grain yield was 17% lower under N2 than under N1. N2 had 13% less panicle number but 5% higher grain weight than N1. The differences in spikelet number per panicle and spikelet filling percentage were not significant between N2 and N1. Aboveground biomass and harvest index were 10% and 9% lower under N2 than N1, respectively. The interactive effects of earthworm cast and N rate treatments on all the yield attributes were not significant. Also because of this, mean data across two N rates were presented for SPAD values in flag leaves (Fig 2). There were no significant differences in SPAD values in flag leaves between EC0 and EC1 at 5 and 10 days after heading, while at 15 and 20 days after heading SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0, respectively.


Rice Yield and the Fate of Fertilizer Nitrogen as Affected by Addition of Earthworm Casts Collected from Oilseed Rape Fields: A Pot Experiment
Effects of addition of earthworm casts on SPAD values in flag leaves in rice.EC0, soil only; EC1, soil: earthworm casts = 4: 1 (w/w). Data are the means across two N rates. Vertical bars represent SE (n = 6).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120869&req=5

pone.0167152.g002: Effects of addition of earthworm casts on SPAD values in flag leaves in rice.EC0, soil only; EC1, soil: earthworm casts = 4: 1 (w/w). Data are the means across two N rates. Vertical bars represent SE (n = 6).
Mentions: EC1 produced 39% higher grain yield than EC0 (Table 2). EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. There were no significant differences in spikelet number per panicle and grain weight between EC1 and EC0. Aboveground biomass and harvest index were 20% and 15% higher in EC1 than in EC0, respectively. Grain yield was 17% lower under N2 than under N1. N2 had 13% less panicle number but 5% higher grain weight than N1. The differences in spikelet number per panicle and spikelet filling percentage were not significant between N2 and N1. Aboveground biomass and harvest index were 10% and 9% lower under N2 than N1, respectively. The interactive effects of earthworm cast and N rate treatments on all the yield attributes were not significant. Also because of this, mean data across two N rates were presented for SPAD values in flag leaves (Fig 2). There were no significant differences in SPAD values in flag leaves between EC0 and EC1 at 5 and 10 days after heading, while at 15 and 20 days after heading SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0, respectively.

View Article: PubMed Central - PubMed

ABSTRACT

The mechanism associated with improvement of soil nutritional status by oilseed rape crop, leading to better performance of rice crop, in rice-oilseed rape cropping systems is little known. The present study was aimed to test the hypothesis that earthworm casts produced during oilseed rape-growing season have positive effects on grain yield and fertilizer nitrogen (N) utilization in the subsequent flooded rice crop. A 15N-tracing pot experiment was conducted to determine the effects of earthworm casts collected from oilseed rape fields on yield attributes in rice and the fate of fertilizer N. Soil treated with earthworm casts (soil: earthworm casts = 4: 1, w/w) (EC1) produced 39% higher grain yield than soil only (EC0). EC1 had 18% more panicle number and 10% higher spikelet filling percentage than EC0. Aboveground biomass and harvest index were higher in EC1 than in EC0 by 20% and 15%, respectively. SPAD values in flag leaves were 10% and 22% higher under EC1 than EC0 at 15 and 20 days after heading, respectively. EC1 had 19% higher total N uptake and 18% higher physiological N-use efficiency than EC0. These positive effects of earthworm casts on yield attributes offset negative effects of decreasing N rate from 0.74 g pot–1 (equivalent to the recommended field rate of 150 kg ha–1) to 0.44 g pot–1 (equivalent to 60% of the recommended rate). Fertilizer N retention rate was 7% higher while fertilizer N loss rate was 6% lower in EC1 than in EC0. Our study suggests that earthworm casts produced during oilseed rape-growing season are expected to have the following benefits on the subsequent flooded rice system: (1) improving growth and physiological processes in rice plants and consequently increasing rice grain yield, and (2) increasing fertilizer N retention rate and hence decreasing fertilizer N loss rate and reducing environmental risk.

No MeSH data available.