Multifunctional Superabsorbent Polymer under Residue Incorporation Increased Maize Productivity through Improving Sandy Soil Properties

Table 4

Crop productivity and economic benefit of maize under multifunctional SAP doses.

Year	Treatment	Heads; ()	Kernels per head (no.)	100–Kernel weight (g)	Grain yield; (kg ha^-1)	Input	Output	Net income
						(Chinese yuan ha^–1)
2016	SAP0	c	b	c	c	2100	d	c
	SAP30	b	b	b	b	3400	b	ab
	SAP60	a	ab	ab	a	4300	a	a
	SAP90	b	a	a	ab	5200	ab	b
	SAP120	b	a	b	bc	6100	c	d
2017	SAP0	d	c	c	c	2100	c	c
	SAP30	c	b	b	b	3400	b	b
	SAP60	a	a	a	a	4300	a	a
	SAP90	b	b	b	b	5200	b	b
	SAP120	c	b	b	b	6100	b	c

The price of maize was 1.6 Chinese Yuan kg⁻¹, SAP price was 30 Chinese Yuan kg⁻¹. Labour cost was 400 Chinese Yuan ha⁻¹, seed and fertilizers costs were 600 Chinese Yuan ha⁻¹, and drip irrigation materials costs were 1500 Chinese Yuan ha⁻¹. Net income (CNYha⁻¹) = Output value − Input value. Where Output value = Maize grain yield × Market price. Input value of SAP treatments = Labor costs + SAP costs + Seed and fertilizer costs + Drip irrigation materials costs. However, Input value of CK = Seed and fertilizer costs + Drip irrigation materials costs + Tractor farming fee (tillage, residue incorporation, and harvesting). SAP0 = SAP 0 kg ha⁻¹; SAP30 = SAP 30 kg ha⁻¹; SAP60 = SAP 60 kg ha⁻¹; SAP90 = SAP 90 kg ha⁻¹; and SAP120 = SAP 120 kg ha⁻¹. Values followed by the same lowercase letter in the same column are not significant according to the least significant different test (LSD 0.05).