Crop Residue Management for Improving Soil Carbon Storage, Nutrient Availability, and Fertilizer Use Efficiency

Bhupinder Pal Singh, Bijay-Singh, Sarah R. Noack, Yunylng Fang, Promil Mehra, Kathryn Page, and Yash P. Dang

CONTENTS

3.1 Introduction............................................................................................................................30
3.2 Crop Residue Management Strategies: Agronomic Implications...........................................31
3.2.1 Soil and Moisture Conservation.................................................................................31
3.2.2 Agricultural Operations..............................................................................................33
3.2.3 Nutrient Management.................................................................................................33
3.3 Crop Residue Management and Soil Carbon Dynamics........................................................34
3.3.1 Crop Residue Management, Tillage Systems and Soil Carbon Storage.....................34
3.3.2 Integrated Crop Residue and Fertilizer Management for Soil Carbon Storage.........35
3.3.2.1 Priming Effect on Native Soil Organic Matter under Integrated

Nutrient and Residue Management..............................................................35

3.3.2.2 Impact of Fertilizer Nutrient Inputs on Microbial Use Efficiency

and Formation of Soil Organic Matter........................................................36

3.3.3 Other Factors Impacting Soil Carbon Dynamics in Agricultural Systems................36
3.3.3.1 Crop Residue Quality...................................................................................37
3.3.3.2 Soil Type and Climate.................................................................................37
3.4 Crop Residue Management and Soil Nitrogen Dynamics......................................................37
3.4.1 Nitrogen Mineralization-Immobilization Turnover in Crop Residue Amended

Soils............................................................................................................................38

3.4.2 Plant Availability of Nitrogen in Soil as Influenced by Crop Residue Management.......40
3.4.2.1 Crop Residue Management and N Nutrition of Crops Grown under

Aerobic (Upland) Soil Conditions...............................................................40

3.4.2.2 Crop Residue Management and N Nutrition of Rice Grown under

Anaerobic (Lowland) Soil Conditions.........................................................41

3.4.2.3 Placement of Crop Residues in the Soil and N Availability to Crops.........41
3.4.2.4 Losses of Inorganic Nitrogen from the Soil-Plant System Amended

with Crop Residues......................................................................................42

3.4.3 Fertilizer Nitrogen Management under Different Tillage and Crop Residue

Management Scenarios...............................................................................................42

3.4.3.1 Changes in Fertilizer N Requirements with Residue Management.............42
3.4.3.2 Timing of Fertilizer N Application to Crops Grown in Residue

Amended Soils.............................................................................................43

3.4.3.3 Fertilizer N Placement Effects in Crops Grown under Conservation

Tillage Systems............................................................................................43

3.5 Crop Residue Management and Soil Phosphorus Dynamics.................................................44
3.5.1 Crop Residue Phosphorus...........................................................................................44
3.5.1.1 Release of Soluble Residue Phosphorus.......................................................44
3.5.1.2 Microbial Processing of Crop Residues.......................................................45
3.5.1.3 Sorption of Phosphorus Released from Crop Residues in Soils..................46
3.5.2 Crop Residue Management and Phosphorus Availability in Soil...............................47
3.5.2.1 Timing and Quantity of Phosphorus Release from Crop Residues.............47
3.5.2.2 Effect of Tillage and Residue Management on the Release of

Phosphorus from Crop Residues and Native Soil Reserves.........................47

3.5.3 Fertilizer Phosphorus Management under Tillage and Residue Management

Systems.......................................................................................................................49

3.6 Crop Residue Management and Soil Sulfur and Potassium Dynamics..................................49
3.6.1 Sulfur..........................................................................................................................49
3.6.2 Potassium....................................................................................................................50
3.7 Conclusions and Future Research Needs................................................................................51

References........................................................................................................................................53