Nutrient reposition and Sequences in soybean based rotations (Parana, Argentina)

Design period: Nutrient reposition and Sequences in soybean based rotations (2006—)

Design Type

Randomized complete block design

Design description

The LTE has six treatments. Each treatment corresponded to a cropping sequence-fertilization strategy combination, including soybean (Sy), wheat (Triticum aestivum L.) as a cover crop (CC), wheat for grain production crop, and maize (Zea mays L.), under no-tillage in a rainfed condition. Experimental plots are 5.3 m wide × 30 m long.

Number of plots

24

Number of replicates

3

Number of harvests per year

2

Crops

Crop	Years grown
soybeans
maize
wheat

Crop Rotations

Sy  2006—

• 1
  soybeans

  0 (kg/ha) N; 0 (kg/ha) P and, 0 (kg/ha) S

Syf  2006—

• 1
  soybeans

  0 (kg/ha) N; 24 (kg/ha) P and, 15 (kg/ha) S (before sowing winter crops)

CC/Sy  2006—

• 1
  wheat

  As cover crop. 0 (kg/ha) N; 0 (kg/ha) P and, 0 (kg/ha) S

  soybeans

CC/Syf  2006—

• 1
  wheat

  As cover crop 0 (kg/ha) N; 24 (kg/ha) P and, 15 (kg/ha) S (before sowing winter crops)

  soybeans

CCN/Syf  2006—

• 1
  wheat

  As cover crop. 46 (kg/ha) N; 24 (kg/ha) P and, 15 (kg/ha) S (before sowing winter crops)

  soybeans

CCN/Syf_rot  2006—

• 1
  wheat

  120 (kg/ha) N; 24 (kg/ha) P and, 15 (kg/ha) S (before sowing winter crops)

  soybeans
• 2
  maize

  120 (kg/ha) N; 24 (kg/ha) P and, 15 (kg/ha) S (before sowing winter crops)
• 3
  wheat

  As cover crop. 46 (kg/ha) N; 24 (kg/ha) P and, 15 (kg/ha) S (before sowing winter crops)

  soybeans

Factor

Factor name

Factor levels

fertilizer exposure

Fertilizer details are described for the experiment rotations above.

Measurements

Variable	Material	Units	Frequency	Scale	Comment
grain yield trait	All crops	kg per hectare	annually		The harvest is doing using a small plot combine
soil total carbon	All crops	mg per kg	usually		Also, in several years there are microbiological measurement (microbial biomass carbon and nitrogen, etc.)
stover biomass	All crops	kg per hectare	anually